CONCORD, Calif. (KRON) — BART blamed high temperatures for an incident in which a train partially went off the tracks in June. The final two cars of the 10-car train went off the tracks between the Pleasant Hill and Concord stations on June 21, disrupting service for several days.

Temperatures were up to 100 degrees in Concord the day of the derailment, and BART said the heat caused the rail to curve and misalign. Rapid temperature changes are causing rails to misalign across the world, according to BART.

Britain’s Network Rail Twitter account posted a series of tweets about how climate change impacts rail lines. It said rails are designed for certain temperatures, and deviation from that causes rails to overheat and expand, bend, or break.

“The climate is changing and this unprecedented weather is hotter than our infrastructure was designed for… If we stressed our rails for exceptionally hot weather, they wouldn’t be safe for the winter and we’d have broken rail because it’s too cold,” tweets from Network Rail said.

On some weeknights after 10:00 p.m. and throughout some Sundays, BART crews will be on the trackway where the train derailed replacing damaged track ties. When this is going on, BART will be on a single-track schedule around the Pleasant Hill Station. On weeknights after 10:00 p.m., there will be delays in both directions of up to 25-30 minutes.

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Out of precaution, BART trains have been going at reduced speeds in the area where the derailment occurred. It also plans to apply speed restrictions for trains when temperatures are forecast to past 100 degrees Fahrenheit.