BART Investigates Second Track Fire in Two Weeks

Updated at 2 p.m.

The track fire at BART's Balboa Park Station early Friday morning that triggered major delays throughout the system was caused by the same kind of equipment failure that prompted the closure of the Walnut Creek station two weeks ago.

On Friday, the blaze slowed down trains to and from the Peninsula.

Agency spokesman Taylor Huckaby said the fire at the Balboa Park stop, located in San Francisco between the Glen Park and Daly City stations, was caused by an electrical arc involving the high-voltage third rail around 4:45 a.m.

A porcelain insulator that covers the third rail caught fire and ignited nearby debris, Huckaby said. The insulators are supposed to prevent electricity that runs through the third rail from grounding and starting a fire, he said.

The same problem caused an equipment fire on the tracks at the Walnut Creek Station on July 30, Huckaby said.  That afternoon, firefighters from the Contra Costa County Fire Protection District extinguished the blaze. The entire disruption lasted about 90 minutes.

Huckaby said it's unclear if there is some sort of systemwide problem with the protective devices.

Friday's fire forced BART to halt trains in San Francisco and the Peninsula at the very beginning of the morning commute. That snarled the entire system.

Huckaby said crews from BART and the San Francisco Fire Department had a tough time extinguishing the blaze.

Crews inspected the tracks and sent inspection trains through Balboa Park to ensure it was safe.

Trains began running through Balboa Park again -- under manual control and using just one track -- shortly before 7 a.m.

Huckaby said single-tracking from Balboa Park to Daly City will likely continue all day Friday. He estimates the resulting slowdown through that section could add an extra 20 minutes to trips.

Damage to the automatic train control system at Balboa Park will be repaired overnight, Huckaby said. That system regulates train speeds from BART's central command center in Oakland.

The cause of Friday's malfunction won't be known until crews can get a look at the insulator when they start those repairs.

The fire took place the day before BART planned to shut down service between Glen Park and Daly City this weekend for previously scheduled maintenance.

KQED's Ryan Levi contributed reporting to this post.