According to an early report, the crew of a toxic train that crashed in Ohio attempted to slow it down before it derailed.
According to federal investigators, the crew was informed of a wheel bearing that was overheating just before the incident.
Toxic chemicals were released as a result of the derailment on February 3 in East Palestine.
On Thursday, Pete Buttigieg, the secretary of transportation, visited the area.
11 of the 38 cars that derailed in the collision were transporting hazardous materials. Later, sick feelings and the deaths of fish and wildlife were reported by the locals.
According to the National Transportation Safety Board's (NTSB) preliminary report, the train's wheel bearing warmed up over a distance of miles prior to the incident.
According to the report, it exceeded the normal temperature by 253F (122C) just before the derailment.
According to the NTSB, an automatic braking system was started as the engineer applied the brakes, causing the train to stop and enabling emergency response to start.
The crew saw fire and smoke after the train stopped, according to the report.
The report, however, gave scant information regarding the precise cause of the derailment and the effectiveness—or lack thereof—of the response.
Authorities were worried that five cars carrying 115,580 gallons (437,500 liters) of vinyl chloride, an odorless gas used to make PVC, might erupt after the fires at the derailment were put out on February 5th.
The substance was then burned under controlled conditions by the authorities, which caused a massive plume of black smoke to be released over the town of East Palestine.
The report, which is preliminary, also discovered no proof that the train was moving faster than the legal limit of 50 mph (80 kph).
According to the NTSB, the investigation is still ongoing, and the investigators will pay close attention to the tank car's design and wheels as well as the burning of vinyl chloride and the accident response.
On the same day that the NTSB report is made public, Pete Buttigieg, the US Transportation Secretary, travels to East Palestine to meet with locals and investigators.
Before his trip, Mr. Buttigieg had come under increasing fire from both sides of the US political divide for what some had characterized as a tardy response to the train derailment in East Palestine.
Many residents of the town criticized state and federal officials, as well as Norfolk Southern, the company that ran the car, for their allegedly inadequate response and lack of transparency.
He was referred to as "an incompetent who is focused solely on his fantasies about his political future" by Republican Senator Marco Rubio, who added that he "needs to be fired.".
Mr. Buttigieg defended his response in a recent interview with CBS News, explaining that he had delayed his visit so that the NTSB could concentrate on its inquiry.
In the immediate aftermath of the crash, he said, "I have followed customary practice for transportation secretaries, letting NTSB lead the safety work and staying out of the way."
