Biloxi man describes 'horrible' scene at fatal train-crossing accident

— -- As the National Transportation Safety Board continues its probe into Tuesday's fatal train crash involving a charter bus carrying 50 people in Biloxi, Mississippi, resident John Kemp described to ABC News today the scene inside the bus just moments after the collision as he sought to rescue some of its passengers.

Kemp said he was sitting at a stop sign, on his way to pick up his child from school Tuesday, when he noticed a "commotion" on the train tracks.

According to the NTSB, a casino charter bus carrying 49 passengers and a driver was traveling over a hump at a grade crossing in Biloxi around 2:15 p.m. Tuesday, when it got stuck on the tracks because of the low-ground clearance.

During a news conference Wednesday, NTSB member Robert Sumwalt said the two-man crew aboard a CSX freight train traveling eastbound placed the train into an emergency stop when it was 510 feet away from the bus. At that time, the train was traveling 26 mph.

Sumwalt said the train, with 52 cars of mixed freight and three locomotives on the front end, was traveling at 19 mph at the time of the collision. The bus was pushed about 200 feet. Sumwalt said four people traveling on the bus at the time were killed.

At least 4 dead, dozens injured after train crashes into charter bus in Mississippi

Passenger says 'train just kept coming' toward bus on tracks

Kemp told ABC News today that about 30 seconds before the collision occurred, he moved his car to avoid getting hit as well. As he made a U-turn, he saw the collision happen. Kemp said he parked his car and tried to jump onto the bus to help the victims but the window was too high. He then drove his car next to the bus, climbed atop the roof and entered the window.

He said the victims were "eerily quiet."

"They were bloodied. Late 60s, elderly people. They were all on the floor except one gentleman. ... He had a cane and he was kind of sitting up in his seat," Kemp said. "It was no crying. It was no screaming. It was just a lot of blood. I saw some limbs broke in places they probably shouldn't have been. ... People couldn't move."

He said the passengers who were killed were outside the bus. Kemp said he thought they had likely been trying to get off the bus at the time.

"Had this been a group of maybe junior high kids, they probably would have all got off the bus," Kemp said. "[It's] just a horrible thing to see."

Kemp suffered cuts to his hands and legs from the broken glass around the window. He said Biloxi police and firefighters arrived within minutes.

"They [the bus passengers] didn't start crying and screaming until we started moving them," he said.

Biloxi police said Tuesday that every passenger on the bus had been injured. The crash occurred at the Main Street crossing, which has flashing lights and crossing gates, CSX said in a statement. CSX said that none of the crew was injured in the accident.

The tour bus originated in Austin, Texas, and was headed to a local Biloxi casino, authorities said.

Sumwalt said determining the length of time that the bus sat on the tracks will be critical to the investigation. He said the train has a forward-facing image recorder that would be recovered and sent to the NTSB lab in Washington, D.C. He said investigators did not yet know whether the bus has a similar recorder.

Sumwalt said according to the agency's preliminary investigation, there have now been 17 collisions since 1976 at this particular grade crossing on Main Street in Biloxi. Three of those collisions have been fatal -- one in 1983, one in 2003 and Tuesday's accident -- according to Sumwalt.

In a statement today, Echo Transportation, the operator of the bus in the crash, said: "First and foremost, our thoughts and prayers are with the victims and families of this terrible tragedy. We are working closely with local, state and federal authorities, providing full cooperation to determine what happened. Due to the ongoing investigation, we cannot provide additional details at this time."

ABC News' Steve Osunsami and Whitney Lloyd contributed to this story.