Q:

Death toll of a week without technology?

So the climax of my urban fantasy story, long story short, involves a supernatural event taking place in the modern time sometime around March on a Saturday, 12:00 PM EST, that renders guns and anything running on electricity (except living things) totally useless — the electricity for a week, the guns forever. I’m trying to wrap my head around what just a week of this would do to the world, with a special focus on the story’s setting of America, and the main question I have would be how many people would likely die by the week’s end?
I don’t want to complicate the question by introducing and explaining the myriad supernatural elements of my story (and I suspect hearing an explanation of what something like this would do to the real world would probably be more than enlightening enough for my purposes), but there are a handful of important things I want to point out about this scenario:

Nobody was on the roads or in the air, at least not in America and most of the rest of the western world. Supernatural events are something of a weekly occurrence that have happened at the same time every week like clockwork for the past half a year, though every one before this has granted humans some new ability. As such, to make sure that none of these events cause any major accidents, travel by road or air is banned for the hour before and after 12:00 EST. So the initial catastrophic traffic accidents this would normally cause are not a concern. To clarify, however, while they knew something would happen at that time, they didn’t have an idea it would be something this huge or negative, so most did not prepare.
Since these are a weekly thing the world is now familiar with, everyone knows that electricity will start working again in a week.
For supernatural reasons that I’ll spare you the details on, mass worldwide prison breakouts start happening at the exact same time.

I’ve been spending a lot of time trying to visualize what the aftermath of this would look like, but I don’t think I can even begin to grasp how many people just a week of this would kill, and the answer to that question is crucial for working out how the book will end and the next book will begin.

A:

manassehkatz provides an excellent answer that covers much of the problems people will face. Some other areas to consider:
The internet is gone. While manassehkatz jokes that teens will die from boredom, the impact is actually far more severe. Much of today's media and knowledge is stored there and is now erased or at best inaccessible. What happens when someone needs to look up a thing, and now that ability is removed? Libraries don't spend near as much money on keeping up-to-date research materials on hand, so vast sums of knowledge are now gone as far as most people are concerned.
Your cars are now useless chunks of metal, plastic, and glass. Without electric spark plugs, no gasoline engine can run. Period. Diesel engines might run, but I guess it depends on how reliant they are on computers nowadays? And of course, even they will require some means to crank, since the battery-powered starter motors are dead.
That last paragraph above just killed entire swaths of your people. Anyone who lives in a city is dead. Period. There are no means to transport goods on a massive scale anymore. This means your city has no food. No food means starvation. You'll have riots before the week ends. And it will be months before order is restored.
Ships at sea will suffer the same fate. Sure, maybe they were at anchor when the surge happened. But now they're dead at sea. All the food being shipped across the oceans is going to rot on board a stranded vessel. I suppose those shipping food can crack open their containers and feed the crew. Otherwise the crew may run out of food before they can reach shore.
Your friendly neighborhood water treatment plant is dead. That's a bad thing. Your water now isn't being pumped from the wells or rivers up to the water towers and out to your citizens. So your citizens are forced to scavenge for whatever water they can find, regardless of how dirty it is.
Your friendly neighborhood sewage treatment plant is dead. That's a bad thing. Now you have raw sewage backing up in pipes, not getting pumped out to the treatment systems or between treatment stages. So the bacteria in them will no longer maintain the balance necessary to survive and treat sewage. This will have long-term impacts for your environment.
Your nuclear power plants are now in melt-down. Sure, they have all kinds of safety measures. But they all rely on various forms of command-and-control systems to maintain them. Those systems are dead, so your reactors are all going to go Fukoshima on you. All of them that weren't already shut down, at least. And there's no way to begin cleanup operations, so the impact will be worse for any such leaks than Fukoshima was/is. (Note, though, that if the world knows these events happen, then it is possible the plants go into a planned shutdown each week during the window. If so, then they're probably okay. Maybe. But it may be impossible to restart the reactors now...)
No one can talk to anyone they aren't nearby. There are no long-range communications methods alive today that aren't electricity-dependent. So we're all in the dark as far as how bad things are at a distance.
No one can manufacture anything. Either because they no lack the means (machines are all dead) or the knowledge (hey, go google how to make a pencil. Oh. Wait. Google is dead...).
Entire industries are dead. Information Technology. Electricians. Electronics / robotics. Publishing. Shipping. Retail. Communications. Entertainment. News. They're all done.
Other power generation facilities may be destroyed as well, or damaged beyond the means to repair without power... Catch-22.
Nations with nuclear arsenals have just lost their control systems. And their electronic defenses. And the electric fences are off for a week. Or more. You've got a high probability that terrorists just walked out with at least some nuclear material from somewhere in the world.  If explosions still work, dirty bombs are a high risk and rogue nuclear weapons are a credible risk, too.
Your nuclear subs just sank. If they are in deep seas, then they imploded and probably released radioactive debris, so now your oceans have contamination which is going to cause ecological troubles. I don't know how much nuclear material will be released or how devastating the impact will be, but there's going to be some kind of impact.
Your satellites are space debris. If power restores before they drift off course, control might be regained before they drift too far and eventually are lost. This means no communication, no weather, no spy satellite coverage. It might be a long time before GPS navigation is an option; how good are you at dead reckoning? Of no consequence to the world as a while, but the ISS is full of dead people now and, depending on how stable the orbits are, may be falling or may be at risk of collision with satellites? Either way, there were no survivors on board.
You don't have any factories that are in production, basically. And some of them, if their production lines were running, probably destroyed or damaged their production machines when the power failed without a proper shut down. Food factories now have rotting food stuck in various stages of the line; once power is restored, they'll spend weeks sterilizing and cleaning everything. That means longer delays before food can get to market. Same for medicine factories. Systems that don't have automatic shut off systems (that don't require electricity to operate) may fail. This might impact production lines that involve gas furnaces.
Your dairy farms are in trouble, since they use automated milking systems. A dairy cow that doesn't get milked twice a day, every day, has problems. So you may have collapsed the world's industrial-scale dairy market.
Any farm crops that rely on automated sprinkler systems may have been ruined.
Hopefully, chemical plants, oil refineries, oil well pumps and offshore drilling platforms, etc. all had the foresight to shut down in preparation for the magic day. Otherwise, they may all go boom.
Again, hopefully, no miners were below ground in the mines when it happened. Because they're trapped, have no fresh air coming in, and won't get rescued.
Fire departments, ambulances, and police cannot respond to problems. And, without phones, they don't know where the problems are. So the risk of catastrophic fire has gone up. WAY up.
Ditto if any forest fires break out that threaten towns.
You've lost all your tsunami warning systems throughout the Pacific Ocean's ring of fire. If an earthquake happens, there will be no notice to warn citizens that a tsunami is coming.
Banks and stock markets are down for a week. There's no way to access the funds in those banks. There is no way to verify the funds exist or how much money is held. The entire stock market is zeroed out until power is back. That's a week where the entire global economy just... STOPPED. We see stock markets ripple over things like tweets or speeches. I cannot imagine what kind of insanity would ensue when power is finally restored and trading is allowed to resume.
People would not be able to buy goods since there's no way for them to validate their bank accounts / credit card accounts to withdraw cash. Any attempt to do "old school paper" credit card slips will be horribly inefficient and ripe for abuse. What happens to people with bills that are due during or immediately after the outage? Auto-draft bills wouldn't pay. Electronic payment methods are down. This is global in scale. The economy would take months to correct from this kind of outage. Would there be a run on banks when power was restored? Would the stock market crash as people liquidated their stocks in favor of more tangible assets that can be traded during disasters? 
These last two paragraphs alone could trigger the kind of panics that were seen last seen in the US in 1929 when the Great Depression really got started.
You've triggered a Dark Age that will end modern, advanced, civilization.
The Amish are your best hope for survival.

A:

This will cause disruption equivalent to a worldwide EMP event. Some likely results:

Plenty of car crashes. Despite the warnings, there will be people on the roads. Not very many plane crashes though because the government has much more control over flight.
A LOT of looting by people who know that there will be no burglar alarms, no calling the cops (unless your store is within a block of a police station) and no bullets to stop you.
Significant deaths of:

Hospital patients, especially anyone in the ICU dependent on medical oxygen, monitoring for serious problems, etc.
Depending on how extensive "no electricity" goes, anyone relying on a pacemaker, automatic defibrillator, etc. will die if they have a heart attack during the week.
Dialysis patients. The least severe cases will last a week. The ones dependent on dialysis every day or every other day might not.
Elderly or other frail people in extremely hot environments that depend on air conditioning for safe temperatures. I know people used to live without air conditioning - but they didn't live in some places they live now, or they would go to the mountains during the worst of the summer. (Cold is not a problem - you can build a fire in your fireplace when the furnace isn't working.)

Some younger people may die of boredom - no internet, no TV, no movies, no Facebook, no online chatting - oh my goodness! They might have to read a book or actually talk to someone. The horror!
Food will not be much of a problem. Peanut butter, crackers, BBQ "whatever is defrosting from the freezer" will work for most people.
But water could be a big problem in many areas. Most places are dependent on electrically pumped water. The water towers (in the areas that have them) will empty quickly and most people don't have enough bottled water on hand to get through the week. Some will have stockpiled water when they got the "no electricity warning", but many people will not. Some of those people will, inevitably, drink contaminated water without proper boiling or bleaching and get sick, though with this only lasting a week not many will die from that.
Fires will be a moderate problem. Many people will be cooking with fire (or heating with fire if the weather is cold) and some of them will not do so in a safe way. Unfortunately, even if they can notify the fire department (no phones), the fire department won't be able to do much because they can't drive the fire trucks and the hydrants in most areas won't have much, if any, water pressure. So there will be some deaths and a moderate amount of property damage due to fires.

I actually don't think the long-term effects will be that bad. Many of the long-term effects theorized for an EMP - e.g., breakdown of society, harvesting and transport of food, medications, etc. simply won't apply with only a one-week lapse.

