Gone at 3:17

At 3:17 p.m. on March 18, 1937, a natural gas leak beneath the London Junior-Senior High School in the oil boomtown of New London, Texas, created a lethal mixture of gas and oxygen in the school’s basement. The odorless, colorless gas went undetected until the flip of an electrical switch triggered a colossal blast. The two-story school, one of the nation’s most modern, disintegrated, burying everyone under a vast pile of rubble and debris. More than 300 students and teachers were killed, and hu