Amtrak Crash - Accident or Attack?

I've got some questions about this:

A tractor-trailer rig hauling gravel east of Reno slammed with explosive force into an Amtrak train bound for Emeryville on Friday, killing at least two people and sending scores to hospitals with injuries.

The fiery collision happened on a lonely, windswept section of Highway 95 about 70 miles from Reno at 11:20 a.m. Smoke from at least two burning cars on the 10-car train could be seen for miles around.

Confirmed dead were the truck driver and a train conductor. At least 100 people were taken by bus, ambulance and helicopter to hospitals in Fallon and Reno, said Nevada Highway Patrol Trooper Dan Lopez. Identifications were not available.

"We're all wondering how in the world this could happen," said Kurt Althof, spokesman for Careflight helicopter ambulance, which flew two women with serious injuries to Renown Regional Medical Center in Reno. "There is absolutely nothing on that highway. It's just desert. How a truck could go into a train like that out there is just bizarre."

The train was the California Zephyr, and it had originated in Chicago. It was due to arrive in Emeryville at 4:10 p.m. There were 204 passengers and 14 crew members on board.

I'd like to know a lot more about the truck driver before I decide this was just an unfortunate accident. The whole thing seems rather unlikely as just an accident.