Michael Kempf, the Amtrak engineer from Savannah who was killed in Sunday’s train wreck in South Carolina, feared for his life after experiencing as many as four other crashes with pedestrians and vehicles that shouldn’t have been on the tracks, his younger brother told The Atlanta Journal-Constitution.

A U.S. Army veteran, Kempf’s harrowing experiences inspired him to see a psychiatrist, who was referred to him by Amtrak and who diagnosed him with post-traumatic stress disorder, said Rich Kempf of Mesa, Ariz. Michael Kempf, 54, who was married and had three grown sons, last spoke to his younger brother by phone Saturday evening.

“I told him ‘Be safe out there’ — from all the other stuff that has happened to him out on that train,” Rich Kempf said. “This isn’t the first time he has been in an incident.”

While working on trains for Amtrak, Michael Kempf encountered people seeking to kill themselves on the tracks as well as vehicles that had gotten stuck at railway crossings, his brother said.

“He has hit people lying on the tracks, and naturally they get killed,” his brother said. “There was another person walking down the center of the track — smashed into them. He hit a car so hard the thing exploded, and part of the car was underneath the train. That person died. He hit a semi that was hung up on the track and plowed into it. And that cracked the windshield on the train, and those train windshields are pretty thick.”

RELATED: NTSB investigating Amtrak train crash that killed Georgia man in S.C.

An Amtrak spokesman declined to comment on Kempf’s medical care, citing employee privacy. But the organization confirmed it offers an employee assistance program providing a variety of services. Amtrak spokesman Marc Magliari added the rail service sponsors Operation Lifesaver, a public safety campaign that says a person or a vehicle is hit by a train in America about every three hours.

Kempf and one other Amtrak employee were killed and more than 100 passengers were injured when their train slammed into a parked CSX freight train early Sunday morning near Columbia, S.C. It’s unknown how many other Georgians were among the injured. Train 91 was traveling from New York City’s Penn Station to Miami with eight crew members and 139 passengers and was planning to make stops in Savannah and Jesup when it crashed. This is Amtrak’s third deadly wreck in less than two months.

Investigators are looking into why a switch was aligned to divert the southbound Amtrak train onto a siding where the CSX freight train was parked, National Transportation Security Board Chairman Robert Sumwalt said. CSX owns and controls the tracks at the site of the wreck, he said. At a news conference Monday, Sumwalt said the Amtrak train was traveling under the speed limit at 50 mph, it sounded its horn and its emergency brakes were applied before it collided locomotive-to-locomotive with the CSX train. The Amtrak train traveled 659 feet on the siding before it slammed into the CSX train, pushing it backward about 15 feet. The NTSB interviewed CSX train officials Monday and will be speaking with the surviving Amtrak crew Tuesday.

“A lot has been done today and a lot needs to be done, but I’m confident our investigators will be able to piece this back together,” Sumwalt told reporters. “We are here to determine not only what happened but why it happened.”

CSX released a statement Monday saying it was working with the NTSB.

“CSX hosts more passenger trains on its network than any other major railroad in the United States,” the company said, “and passenger rail remains one of the safest ways to travel.”

Amtrak CEO Richard Anderson told reporters Sunday that the rail service is “doing everything in our power to operate a safe and reliable railroad.”

“We always prioritize safety as the very first priority at Amtrak and will continue to do so,” Anderson, the former head of Atlanta-based Delta Air Lines, said in a conference call.

Palmetto Health hospitals received 62 patients from the crash, including 59 adults and three children. Of them, 56 have been released. Two of the remaining patients were in critical condition Monday.

The son of a U.S. airman, Kempf grew up in North Dakota. He spent 20 years in the Army, serving in Panama and South Korea. After he retired from the military, Kempf went to work at CSX as a conductor. He spent about nine years there before taking a job at Amtrak. Rich Kempf said his older brother was fond of Harley-Davidson motorcycles and had a friendly demeanor.

“He was the type of guy who could walk up to a stranger and start a conversation and within five or 10 minutes they would be on a first-name basis with each other,” Rich Kempf said, “and it was almost like they knew each other forever.”

Rich Kempf, 53, a crane operator, said he wants to know what the railroad industry will do to prevent another accident like the one that killed his brother Sunday.

“What are they going to do about it?” he said. “What are they going to do to stop this from ever happening again?”