WMATA investigates smoke incident at Friendship Heights Station

The Washington Metropolitan Area Transit Authority (WMATA) yesterday released preliminary findings of its investigation into an April 23 smoke incident outside the Friendship Heights Station in Washington, D.C.

Although the agency hasn't yet identified the root cause of the incident, investigators have eliminated power cables as a contributing factor, WMATA officials said in a press release.

The investigation is focused on a metal part of a rail car that became dislodged and made contact with the third rail. The contact is believed to have caused a loud noise, flash and smoke, agency officials said.

In addition, investigators have conducted inspections of all power infrastructure in the tunnel, as well as all rail cars on the train involved in the incident.

WMATA and the Federal Transit Administration (FTA) are continuing to investigate the cause of the incident. No injuries were reported.

In January 2015, WMATA experienced a similar smoke incident that left one passenger dead and more than 80 others injured.

News of the latest smoke incident comes less than a week after the FTA ordered WMATA to immediately address several safety issues.

In an April 18 letter to WMATA General Manager and Chief Executive Officer Paul Wiedefeld, FTA officials said numerous defects were uncovered during their recent "safety blitz" inspection of Metrorail track and power systems. Those defects could affect evacuations during an emergency, the letter said.