It was a nightmare scenario by any reckoning: workers installing piping at a school accidentally set off a release of gas and ran to warn everyone to evacuate. Some people made it out of the building before a thunderous explosion destroyed it. Others didn’t. That’s what occurred on the morning of August 2, 2017, at Minnehaha Academy, a private school in Minneapolis, Minnesota. The blast killed two employees, custodian John Carlson and receptionist Ruth Berg, and seriously injured nine others.