BART says heat played role in train's partial derailment

BART service on the Yellow line was stopped in both directions during the Tuesday evening commute because of a train derailment– making travel difficult for dozens of people trying to get home.

By Wednesday before 5 a.m., trains were able to single track, causing just a 15-minute delay.  

BART officials confirmed the derailment between Pleasant Hill and Concord stations might have been caused the excessive heat that permeated the region. The heat causes the tracks to curve, BART said. 

The issue was first posted on social media just before 6 p.m. Approximately 50 passengers were evacuated from the train. A small number of passengers reported minor injuries, Contra Costa County Fire Protection District said.

One person went to the hospital for back pain.

"We have a crew of 70 people that will work overnight to move the train then cut out the damaged track and replace it," BART officials said from their Twitter account. The affected train will likely not be put back into service before 5 a.m. Officials said the opposite track is not damaged and that trains will run on it.   

SkyFox flew above the derailment and did notice one of the train cars from the 10-car train was askew from the rest that remained in alignment. BART in the past has had to keep an eye on their tracks in cases of extreme heat to monitor for moving or buckling. 

Wire services contributed to this report.