East Palestine, Ohio: Crew tried to slow train before toxic wreck - NTSB
The crew of a toxin-laden train that crashed in Ohio tried to slow it down before it derailed, according to a preliminary report.
Federal investigators said the crew was alerted about an overheating wheel bearing shortly before the incident.
The 3 February derailment in East Palestine led to the release of toxic chemicals.
Transportation Secretary Pete Buttigieg was in the town on Thursday.
A total of 38 cars derailed in the crash, 11 of which were carrying hazardous materials. Residents later reported feeling unwell, as well as fish and wildlife dying.
The preliminary report from the National Transportation Safety Board (NTSB) found that a wheel bearing on the train had heated up over several miles before the incident.
Shortly before the derailment, it reached a "threshold" level of 253F (122C) above the normal temperature, the report said.
As the engineer applied the brakes to the train, an automatic braking system was also initiated, allowing the train to stop and response efforts to begin, according to the NTSB.
"After the train stopped, the crew observed fire and smoke," the report said.
The report, however, provided few details as to what exactly caused the derailment and how effective - or not - the response was.
At a news conference in Washington DC, NTSB chair Jennifer Homendy said that the crash was "100% preventable".
"We call things accidents," she said. "There is no accident. Every single event we investigate is preventable."
Ms Homendy added that the NTSB has completed its investigative work in the field. In the spring, it plans to hold rare "investigative hearing" in East Palestine to question invited witnesses.
She said the hearing would help inform the public, collect information, discuss possible solutions and "build consensus for change".
A final report will likely take between 12 and 18 months, Ms Homendy said, although the NTSB will "not hesitate to issue an urgent safety recommendation" if required.
Fires at the derailment were contained by 5 February, but authorities remained concerned that five cars carrying 115,580 gallons (437,500 litres) of vinyl chloride - a odourless gas used to make PVC - might explode.
Authorities then conducted a controlled burn of the substance, sending a huge plume of black smoke over the small town of East Palestine.
The report - which is not final - also found no evidence that the train was traveling above the speed limit of 50mph (80kph).
The NTSB said that its probe is ongoing and that investigators will focus on the wheels and tank car design, as well as on the burning of the vinyl chloride and accident response.
In a statement published Wednesday, the Transportation Communications Union - which represents railroad workers - said it believes the crash may be partly the result of rail companies prioritising profits of safety.
"For the past several years, rail labour unions - ourselves included - have been ringing the alarm bells about the dangers of the cost-cutting business model," it said.
While the firm that operated the train, Norfolk Southern, has not commented on the investigation, it has defended its response.
Speaking to CNN on Wednesday, CEO Alan Shaw said that the company has already paid $6.5m (£5.4m) to residents living near the derailment, and vowed to continue helping East Palestine recover.
The release of the NTSB report comes on the same day as US Transportation Secretary Pete Buttigieg visited East Palestine to meet with residents and investigators.
Ahead of his visit, Mr Buttigieg had faced increasing criticism from both sides of the US political spectrum for what some described as a slow response to the train derailment in East Palestine.
Many in the town criticised what they said was an unsatisfactory response and lack of transparency from state and federal officials, as well as Norfolk Southern.
Republican Senator Marco Rubio, for example, called him "an incompetent who is focused solely on his fantasies about his political future", adding that he "needs to be fired".
Speaking to reporters in East Palestine on Thursday, Mr Buttigieg criticised Norfolk Southern and accused the administration of former President Donald Trump of working to loosen regulations.
"Industry goes to Washington and they get their way," he said. "They got their way on a Christmas tree of regulatory changes that the last administration made."