Here's the most thorough explanation yet for the train derailment in East Palestine

https://www.npr.org/2023/02/23/ [login to see] /east-palestine-train-derailment-ntsb-preliminary-report-wheel-bearing
The operators of a Norfolk Southern train carrying hazardous chemicals near East Palestine, Ohio, earlier this month tried to stop the train after a wheel bearing overheated to a dangerous degree, the National Transportation Safety Board said.

But by the time an alarm rang to alert the crew of the danger, the bearing was already so compromised that it failed as the train was still coming to a stop, officials said — a revelation that raised questions about whether Norfolk Southern's safety sensors and procedures were sufficient to prevent a catastrophic failure.

"Roller bearings fail. But it's absolutely critical for problems to be identified and addressed early so these aren't run until failure," said NTSB Chair Jennifer Homendy at a Thursday press conference.

A preliminary report released by the NTSB Thursday stopped short of declaring a conclusive cause of the derailment. But the report, along with additional details shared by officials, together offered the most detailed explanation yet of what may have sent the train off the tracks.