CHESTER, Mont. (AP) — Trevor Fossen was running late for a wedding Saturday afternoon when he turned onto a dusty, gravel road in rural Montana as a westbound train approached the crossing in front of him.

The train never made it to the crossing. The next thing Fossen saw was a wall of dust fill the sky.

"I started looking at that, wondering what it was, and then I saw the train had tipped over and derailed," said Fossen, a 29-year-old farmer.

It was an Amtrak Empire Builder en route from Chicago to Seattle that had derailed, killing three people and injuring dozens of others. Investigators st...