- The Washington Times - Saturday, July 7, 2012

Metro officials on Saturday said excessive heat was the probable cause for a train derailment Friday in Prince George’s County.

Investigators said a “heat kink” due to extreme high temperatures and direct exposure to sunlight likely caused the rails to expand, resulting in the derailment.

The derailment was reported on the inbound stretch of the Green Line near the West Hyattsville Station around 4:45 p.m. The last three cars of the train derailed as it was going through an underground tunnel. About 55 passengers had to be evacuated from the train through a fan shaft. No serious injuries were reported.

Metro officials said in a news release that heat kinks, or short sections of misaligned track, occur when the expanding rail cannot be constrained by cross-ties and warp outward from the normal alignment.
Metro officials said the investigation into the incident is ongoing.

Green Line service between Fort Totten and Prince George’s Plaza was suspended through Saturday, as Metro crews worked to re-rail the derailed cars and repair damaged track, transit agency officials said.

Shuttle buses were operating between the Fort Totten, West Hyattsville and Prince George’s Plaza stations. Normal service was expected to be restored for Monday morning’s commute.

As a precaution, trains traveling above ground were slowed to 35 miles per after the derailment, officials said.