Daniel Zwerdling

Michael de Yoanna/Colorado Public Radio

Staff Sgt. Eric James, an Army sniper who served two tours in Iraq, paused before he walked into a psychiatrist's office at Fort Carson, Colo. It was April 3, 2014. James clicked record on his smartphone, and then tucked the phone and his car keys inside his cap as he walked through the door to the chair by the therapist's desk.

You might think that everything would have changed for the chemicals industry on April 16, 1947. That was the day of the Texas City Disaster, the worst industrial accident in U.S. history. A ship loaded with ammonium nitrate — the same chemical that appears to have caused the disaster last month in West, Texas — exploded. The ship sparked a chain reaction of blasts at chemical facilities onshore, creating what a newsreel at the time called "a holocaust that baffles description."