A log truck overturned in Robbins, Tenn., a few weeks ago, and the driveshaft exploded.

Tracy Jeffers, safety officer for the South Scott Volunteer Fire Department in Robbins, wrote to me that he never had witnessed anything like that in his 28 years of service, so wanted to caution others about the potential danger with driveshafts.

“During the welding process, welding gases became trapped inside the driveshaft; when it became too hot, it exploded those gases,” Jeffers theorized after doing some research. “It was a tremendous explosion.”

Soon, I contacted Ralph Craven — one of the founding members of the National Association of EVTs, who often is called as an expert witness during trials involving fire apparatus — and asked him about the exploding driveshaft.

“Exploding driveshafts can be a very serious problem,” he said. “I had one blow up when we were fighting a barn fire. The driveline was laying on the ground in a bunch of old hay that was on fire. It blew up and went flying through the air with a very sharp edge. ... I don't know what the odds of this happening but it is a real possibility.”

Craven said that he has always discussed the dangers of possible driveshaft explosions during his auto extrication classes.