TEXAS - An Amtrak train bound for Fort Worth stalled Saturday for more than two hours in Denton County, leaving about 170 passengers baking in 100-degree heat with no air conditioning.

Local firefighters provided ice water and other aid while arrangements were made to get the stranded riders out of the heat, said Tom Reedy, a Denton County sheriff spokesman.

"There are no medical problems so far," he said Saturday afternoon. "Everybody's in good shape."

The southbound train struck a plow attached to a tractor at about 9:40 a.m. at a dirt road crossing in Davis, Okla., about 80 miles north of Sanger, said Vernae Graham, an Amtrak spokeswoman.

"The driver was trying to cross and wasn't able to get the plow completely off the track," she said. There were no injuries, and the damage to the train appeared to be minor, she said. The train's maximum speed is 79 mph, but it's unclear how fast it was traveling at the time.

Amtrak officials are investigating whether that collision caused the train to stall at about 12:30 p.m. near Sanger.