The fatal Colorado train derailment incident that killed a semi-truck driver may have been caused by a broken rail.

The incident involved a train that was hauling 124 cars of coal and occurred on Sunday afternoon on a bridge over Interstate 25 north of Pueblo. The preliminary assessment of the National Transportation Safety Board (NTSB) determined that the bridge collapsed after the train derailed.

Colorado Train Derailment

This sent coal and mangled train cars across I-25 and closed the busy route between Pueblo and Colorado Springs. A total of 30 train cars derailed and investigators who were at the scene of the incident on Tuesday tried to figure out what resulted in the broken rail and why warning systems did not alert the train's crews.

Furthermore, federal investigators will analyze the adequacy of prior track inspections as well as the condition and maintenance history of the bridge. The federal agency is set to release its preliminary report within 30 days. However, a final report could take up to two years to be completed, as per the Colorado Sun.

The NTSB said that the broken rail that is suspected of causing the derailment was located east of the bridge over I-25. On Tuesday, both northbound and southbound lanes of I-25 were still closed to allow crews to clear debris from the road.

BNSF Railway expects that the cleanup operations will be completed by Wednesday, which is when engineers and maintenance crews from the Colorado Department of Transportation (CDOT) will assess the damage and determine what repairs would be needed in order to reopen the busy highway.

Officials advised drivers who were heading south to use Colorado 115 until they get to Penrose, before heading east on U.S. 50 toward Pueblo. On the other hand, Northbound drivers were told that they could exit the interstate at U.S. 50 and go west toward Pueblo West, then north on Purcell until they get to I-25.

Read Also: Six-Year-Old Palestinian-American Boy Stabbed 26 Times, Says Goodbye to His Mother 

Unfortunate Tragedy

The truck driver who was killed in the derailment was identified as 60-year-old Lafolette Henderson from Compton, California. His daughter Endaya Jenel said that he is survived by six children and 15 grandchildren, according to the Associated Press.

Jenel noted that every week, her father would mail a toy car to her 16-month-old son from across the country. She said that some of the mailings have not yet been opened and she plans to save them until her son is a little bit older. The victim's daughter also gave birth to a baby last week whom he has not yet met in person.

In a social media post, Jenel said that she would no longer get another call from her father while he was on the road. She revealed that she would talk to him for several hours on the phone at 5:00 a.m.

In a statement, Secretary of Transportation Pete Buttigieg said that he has already communicated with Colorado Gov. Jared Polis about the incident. Buttigieg added that Polis has been briefed by the Federal Railroad and Federal Highway Administrations, said CNN.

Related Article: More Improperly Store Corpses Found in Return to Nature Funeral Home