CAYCE — The passenger train abruptly switched tracks. Its horn broke the quiet of the early Sunday morning. The engineer threw off the throttle and slammed on the emergency brakes.

In less than 10 seconds, a routine trip from New York to Florida became chaotic and deadly.

The crew aboard the Amtrak train that barreled headlong into an idle CSX freight engine near Cayce  had only 659 feet to react by the time the train veered onto the wrong section of track, officials with the National Transportation Safety Board said Monday.

Speeding at more than 50 miles per hour, Amtrak 91 covered the distance — less than the length of two football fields — quickly. 

It plowed viciously into the awaiting freight train, shoving the engine and 35 other railcars back more than 15 feet, according to investigators. The Amtrak cars, filled with 139 sleepy passengers and eight crew members, shuddered and crumpled.

In the end, the crash killed Michael Cella and Michael Kempf, the train's conductor and engineer, and sent more than 116 people to Columbia-area hospitals, where six of them remained Monday. Two are in critical condition.

The federal investigation into the accident is only beginning. But information obtained from the Amtrak train Monday showed the passenger cars were travelling the speed limit for that section of rail, according to investigators. 

Robert Sumwalt, chairman of the National Transportation Safety Board, said the federal agency's initial investigation focused on the mechanical switch that sent the Miami-bound train down the wrong rails at 2:34 a.m., Sunday.

The track where the accident took place was switched and locked with a padlock earlier when the CSX freight train was moved from one track to another after unloading automobiles. The tracks and switches are owned and operated by CSX, but NTSB officials would not say if the actions of CSX employees were responsible for the deadly accident.

By late Monday evening, federal investigators interviewed four employees with CSX to help determine what went wrong. Federal officials plan to interview the remaining Amtrak crew members Tuesday, said Sumwalt, a Columbia native. 

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

Improperly set switches are one of the top causes of train wrecks in South Carolina, causing about a tenth of all accidents on the rails over the past decade, according to a Post and Courier review of safety records. When human error causes crashes, switching issues are responsible a quarter of the time.

They've also been responsible for some of the most harrowing train crashes in the state's recent history, incidents that echo Sunday's fatal wreck outside Columbia.

They include a crash in Allendale County, where a CSX train was switched onto a rail spur in the early hours of the morning of January 2015 and careened into parked tankers carrying hydrochloric acid. The two crew members on board were hurt, and 19,000 gallons of acid spilled out, according to the Federal Railroad Administration.

Investigators determined a vandal changed the signal that should have alerted the train's crew to the switch.

In 2005, workers parked a Norfolk Southern train outside a factory in Graniteville at the end of a long shift — one that investigators later ruled excessively long. The crew forgot to change the switch that led into the small Aiken County town. Later that night, a train carrying chlorine gas followed their path into town and smashed into the parked rail cars. The collision and gas fumes killed nine and hospitalized 75 others. Nearly 600 people were taken to hospitals.

James Hall, who was chairman of the NTSB under President Bill Clinton, said problems with incorrectly set switches highlight the need for more redundancy in the railroad industry. Without better safety measures, he said, one crew’s oversight can cause a deadly collision.

Those problems are especially pronounced in the South, which has more manually operated rail switches than other parts of the country, Hall said. The switch in Cayce was also operated by hand.

The crash in Cayce renewed calls for a crash-prevention system known as positive train control, which has been delayed for years and won’t be fully implemented until 2020. Hall said the NTSB’s calls for such a system predated his time on the board, which began in 1993.

“The rail industry itself has historically dragged its feet on progress in terms of rail safety unless it benefitted their bottom line,” Hall said. Problems with switches and positive train control “both reflect a bad safety culture in the railroad industry,” he said.

Sumwalt, the current NTSB chairman, said signals were down Sunday morning because CSX was installing equipment for the crash-prevention system. He did not say what, if any, role the downed signals played in the accident.

Sumwalt told reporters Sunday the positive track control automatic braking system could have prevented the Cayce collision. Congress has extended deadlines to install the system in place until the end of this year, but railroads could get further delays until 2020. 

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Columbia Bureau Chief

Shain runs The Post and Courier's team based in South Carolina's capital city. He was editor of Free Times and has been a reporter and editor for newspapers in Charlotte, Columbia and Myrtle Beach.