The Amtrak conductor who trained the engineer of Amtrak 188 has told the Tampa Bay affiliate of ABC News he thinks it’s likely the derailment was caused by a projectile of some kind striking the engineer’s compartment window. (Video at the link.)

“My take on the whole thing is there must have been impact on the window to get that kind of damage,” Callanan tells ABC Action News in an interview recorded overnight in Tampa. “The whole train, including the engine, has what we call “FRA Type II glazing,” which is essentially bullet-proof glass, throughout the whole train. So it takes a lot of force to even crack the window,” Callanan said. “And when I saw that on the right-hand side of the engine, it looks like it struck something and I don’t think it was the guy hitting his head.”

Callanan says he’s been talking with colleagues along the East Coast, who describe the engineer, who operates the train, as “a very good engineer.”

What’s more, Callanan says he doesn’t think an engineer would speed, let along double the speed limit to above 100 miles per hour, just to make up 10 or 20 minutes.

“It’s not worth it,” says Callanan.

So what happened? Callanan and his colleagues have a theory they don’t think is all that far-fetched.

“We have had our trains stoned before. All kinds of stuff happens on the Northeast corridor. If you name it, I’ve seen it. Baltimore, we’ve had children stoning the train, throwing rocks at the train. That particular area, North Philly, is a bad area,” says Callanan.

Here’s a closeup of the front of the train after the crash, and the window does appear to be damaged right in front of where the engineer sits.

It’s an interesting theory, and in fact, two other trains were indeed hit by projectiles on the same evening, shortly before Amtrak 188 crashed, and conductor Brandon Bostian reportedly suffered a concussion and needed 14 stitches for a head wound.

Please note that I’m not endorsing this theory. It’s probably just coincidence, but the fact that two other trains in the same area were hit and damaged by projectiles on the same night takes it out of “crazy fantasy” territory.

A Reuters report has more details that could support this theory: Burst of Speed Before Amtrak Train Crash at Heart of Investigation.

Charles Culver, a certified conductor and engineer based in Texas who is not connected to the investigation, said the throttle of the locomotive that Bostian was operating has eight settings, with each click forward accelerating the train. The eighth setting is the highest.

Culver, who runs a rail consulting firm, said it does not take much force to move the throttle forward and it was possible the engineer could have fallen and moved the throttle. Passenger trains, unlike freight trains, can increase speed rapidly, he said.

“In order to increase the speed as much as it was increased in this case, you would have had to really, really move the throttle,” Culver said. “Frankly, I am puzzled about the whole thing. It’s not like it was a few miles per hour over the speed limit.”

Culver said it was possible the engineer lost awareness of the train’s location due to some medical condition, such as a stroke.

Assistant Amtrak conductor said she heard the engineer say the train had been struck by something before the crash http://t.co/IdaPEZdTNf

— The New York Times (@nytimes) May 15, 2015