Cimarron - An Amtrak train carrying 131 passengers derailed in rural Kansas early on Monday, moments after an engineer noticed a significant bend in a rail and applied the emergency brakes, an official said.At least 32 people were hurt, two of them critically, authorities said.Hours later, investigators said they were checking whether a vehicle crash may have damaged the track before the accident.The train known as the Southwest Chief was apparently travelling at about 120km/h when the engineer noticed the deformity in the rail and pulled the brakes, a US official told The Associated Press. The official spoke on the condition of anonymity because that person was not authorized to speak publicly about the federal investigation.The train, which also had 14 crew members, was making a 43-hour journey from Los Angeles to Chicago when it derailed shortly after midnight along a straight stretch of tracks in flat farmland near Cimarron, a small community about 250km west of Wichita. Eight cars derailed, and four of them ended up on their sides.Thirty-two people were taken to hospitals for treatment, and nearly all of them had been released by late morning, Amtrak said.One crew member was treated at the scene.The injured included two people who were airlifted to Amarillo, Texas, said Caytie Martin, a spokesperson for the Northwest Texas Healthcare System. They were listed in critical condition.Authorities were examining tyre tracks leading to the rails. The damage did not appear to be intentional, Gray County sheriff's Deputy JG Sharp said.Investigators from the National Transportation Safety Board were also at the scene.Really bumpyDaniel Aiken, 21, of Lenexa, Kansas, said he heard screaming as he climbed out of an overturned car. He stopped to smell a fluid that was flowing through the car, fearful that it was fuel, but was reassured when he realized it was water."Once people realized the train wasn't going to blow up, they calmed down," he said.Passenger Daniel Szczerba described the chaos for Wichita TV station KWCH."All the lights went out. It was dark," passenger Daniel Szczerba told Wichita TV station KWCH. "People travelling in groups (of) four or five got thrown around the car as it turned over and lost people as they were trying to get out of the emergency exits."Amtrak did not say how fast the train was travelling when it derailed, nor did it immediately respond to calls seeking further details. The area was foggy at the time, but it was not immediately known if the weather played any role.Andy Williams, a spokesperson for BNSF Railway, which owns the track, said the derailment was not caused by poorly maintained track. He said the track is inspected twice a week and meets Federal Railroad Administration guidelines.Uninjured passengers were taken to the Cimarron community centre to wait for Amtrak to make arrangements to transport them to their destinations.Kelsey Wilson, 21, said she woke up when she felt the ride "getting really bumpy" and the train started to shake. Wilson, who was returning to Truman State University in Kirksville, Missouri, after spending spring break at home in Pueblo, Colorado, said her car disconnected from the one in front and that she hit her head as it overturned.Wilson said she escaped through the top of the flipped car then slid down the side before she "passed out." She was taken to a hospital and released with a neck brace.Keith Holloway, a spokesperson for the National Transportation Safety Board, said in an email that the agency was sending a team to investigate. He said more information would be released once the team arrived in Kansas.