Gas Leak Scare Causes Delays for Red Line Subway Riders

A false alarm of a methane gas leak disrupted MTA Red Line service for about 90 minutes during the Tuesday morning commute, causing at least one train to be evacuated and forcing many riders along the 17.4-mile line onto shuttle buses.

Ordinarily, the system would have been back in service within about 20 minutes, officials said. But someone inadvertently tripped a fire-suppression system that sent water into the subway, automatically cutting power to the electric trains.

“Unbelievable. It’s Murphy’s Law at work,” said Abdul Zohbi, safety manager at the Metropolitan Transportation Authority.

But he said that given the potential danger of explosion if the leak had been real, “the system did what it was supposed to do. We want to play it on the safe side.”

MTA is conducting a review to prevent a recurrence of the error, spokesman Ed Scannell said.

Officials did not know how many riders were affected. The Red Line, one of the four rail routes operated by MTA, averages 117,000 boardings daily. Scannell said the entire Red Line experienced delays, except the North Hollywood spur, which continued to operate as far south as the Vermont-Beverly station.

MTA used a “bus bridge” to ferry passengers from stopped trains to the stations where they normally disembark.

The trouble began at 6:50 a.m. when technicians in an MTA control center received a computer-screen warning of either methane or hydrogen sulfide gas in the tunnel near the Westlake/MacArthur Park station. The Los Angeles Fire Department was dispatched to check it out while technicians activated an emergency ventilation system.

Engineers were alerted by radio. Trains headed toward the supposed leak were either held at nearby stations or stopped on the tracks.

The Fire Department found no leak. But at 7:20 a.m., just as the system was returning to normal, someone with official access to emergency controls hit the fire-suppression button, cutting power to at least four trains on the line. Three were at station platforms. One was in the subway but was evacuated without incident, Scannell said.

Normal train service resumed at 8:35 a.m.

In case of fire, the fire-suppression system is designed to send water into a tunnel from beneath the tracks.

The gas alarms are part of a sophisticated detection network throughout the 73-mile MTA rail system that detects smoke, seismic events and water leaks near tracks.

Scannell said the gas sensors go off about four times a year, but no significant leak has ever occurred in the subway.

Zohbi said methane or hydrogen sulfide gas, which is also explosive, can accumulate in rail subways because of natural deposits in the Earth or oil well activity.