On Wednesday, many Americans expressed their "thoughts and prayers" for the victims of a mass shooting in San Bernardino, CA, which left 14 people dead and 21 people injured. But the California shooting wasn't the only one that took place in the United States on Wednesday. In a separate event, a gunman in Savannah, GA, killed one woman and injured three men.A spokesperson for the Savannah-Chatham Metropolitan Police Department told The Washington Post that it hasn't arrested a suspect in Wednesday's shooting. The department is also investigating the possibility that there were two shooters . Separately, Savannah was also home to a domestic shooting on Thursday morning.The Savannah-Chatham Metropolitan Police Department has released the names of the four victims as Jamond Heyward, 17; Brandy Council, 34; Jarrett Myers, 40; and Jeran Washington, 52. Council was killed in the shooting, and Heyward, Myers, and Washington were treated at the Memorial University Medical Center. Even local media seemed to focus its attention on San Bernardino on Wednesday, although an article on Savannah's WSAV.com covered the Georgia shooting in four sentences.Shannon Watts, the founder of Moms Demand Action for Gun Sense, a part of Everytown for Gun Safety, believes that while many Americans may be desensitized to news of gun violence, it doesn't mean they aren't fighting back.Watts told Refinery29 that the United States has a higher rate of gun violence than other developed countries because of its lax gun laws, but activist organizations like hers can make a real difference for gun law reform, even if it's just at the local level. Watts explained to Refinery29 that while Congress may not be taking action on gun control, many reforms to background checks and other gun control regulations have been passed at the state level since Sandy Hook."When the lawmakers won't do the right thing, we're doing things like ballot initiatives," Watts told Refinery29, adding that many gun control ballot initiatives have been successful at the state level. "We've passed laws in more than a dozen states to keep guns out of the hands of domestic abusers," Watts added. She also noted that Moms Demand Action for Gun Sense and Everytown for Gun Safety have successfully convinced companies such as Starbucks and Chipotle to change their gun policies.And as for the desensitization of Americans, Watts noted that many Americans don't realize, or don't think about, the fact that an average of 88 Americans are killed by guns every day. Different organizations count the number of mass shootings in the United States differently, too. For example, after Wednesday's shooting in California, The Washington Post reported that there have been 352 mass shootings in the United States this year, citing data from the Mass Shooting Tracker.The data includes shootings where four or more people are injured or killed by gun violence in a single incident. But other organizations, including Everytown for Gun Safety, use the FBI definition of mass shooting and only count events where at least four victims are killed, not shot, by guns. By that definition, there have been 21 mass shootings in the United States this year.After every mass shooting in the United States, activists urge lawmakers to take more action on gun control. And however you define mass shootings, it's important that we work to stop these events from taking place. Watts noted that this doesn't have to include outlawing guns — many members of her organization own guns — but enforcing rules to keep them out of the hands of people who shouldn't have them. That's something both sides of the aisle can agree on.