The engineer killed when the Amtrak train he was driving slammed into a parked freight train in South Carolina had seen a counselor to help him cope after being rattled by a previous train wreck, his mother said. Within the past year, Michael Kempf 's train hit a vehicle at a rail crossing, Catherine Kempf, 86, said in a Monday telephone interview from the Savannah, Georgia, home she shared with her son and his wife. Catherine Kempf said she didn't remember specifics about the collision on her son's normal route in the Carolinas, but she said the wreck left him upset. Michael Kempf, 54, knew "he had people's lives in his hands," she told The Associated Press. Kempf and conductor Michael Cella, 36, of Orange Park, Florida, were killed in the train crash early Sunday near Cayce, South Carolina. More than 100 passengers were treated at hospitals for injuries. It was the third fatal Amtrak train crash in less than two months. Cella's wife, Christine, declined to talk to the AP about the man who had been her partner for about 20 years. "There's just ... it's too much right now," she said by phone. Asked for details about Kempf's previous accident, Amtrak spokesman Marc Magliari said, "We will not be confirming that assertion." Another Amtrak spokeswoman, Kimberly Woods, said the company does not to provide information about employees. Federal Railroad Administration data show at least four crashes in North Carolina and three in South Carolina during 2017 involving Amtrak trains and cars or trucks on the tracks. One last month left two motorists dead after they tried to cross railroad tracks ahead of an oncoming Amtrak train in rural North Carolina. Catherine Kempf said her son previously worked for CSX but joined Amtrak because the passenger rail service gave him adequate notice about when he was needed to work. CSX expected Michael Kempf to "stand by the phone all the time, so he had to be on call. At Amtrak, they didn't do that," Catherine Kempf said. Michael Kempf began working for railroads after retiring from the Army, where he worked as a tank driver. As a child in North Dakota — where is father worked for the Air Force — Michael liked to ice skate and play hockey, but his more recent passion was riding his motorcycle, his mother said. Sunday's crash happened after a switch was left locked in a position and sent the Amtrak train off the main line and on to a side track where it hit the parked freight train, investigators said. The National Transportation Safety Board is reviewing whether a signal further up the track was red to warn the passenger train it needed to stop.