The Keystone 1 pipeline was touted as being techno-magical safe, also, with experts predicting no more than one spill every seven years on average. Naturally, there were  equally techno-magical backup safety processes to address that one leak every seven years. It leaked 12 times the first year, and has had 30 leaks total.   

Even the very best technology requires ongoing maintenance by people. People don't improve like generations of technology do. They are as flawed as ever, screwing up bigly, like the Exxon Valdez, and the Deepwater Horizon explosion. Tuna and some other marine populations in the gulf will never recover, biologists say.

People also fail routinely to anticipate the consequences of their actions, just as we have failed to anticipate what burning fossil fuels would do to climate, even though it has been known for over 150 years that adding CO2 to the atmosphere would cause a greenhouse effect. The extent and rapidity of the changes worry all the scientists lately.