This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

(CNN) — Metro systems that travel underground in the United States may be unprepared for smoke or fire emergencies, National Transportation Safety Board spokesman Keith Holloway said Tuesday.

The board wants a nationwide audit of transit systems, with emphasis on trains that operate in enclosed tunnels.

The huge undertaking would be the first of its kind, Holloway said.

The call for an audit comes as investigators look into a January 12 fatal accident that happened near the L’Enfant Plaza Metro Station in Washington. An electrical malfunction inside the tunnel caused train cars to fill with smoke. Passengers who were trapped inside said they struggled to breathe. One female passenger died.

The Washington Metro system, operated by a multistate compact known as WMATA, has ventilation fans at strategic locations designed to remove smoke and heat from the tunnels, but investigators found they were inadequate.

“The ventilation strategy that WMATA implemented during the accident was not consistent with best practices.” the NTSB said.

Investigators also found Metro employees had no written procedures for dealing with ventilation during smoke and fire events underground.

“The investigation to date has revealed that WMATA does not currently have the means to determine the exact location of a source of smoke in its tunnel network,” the NTSB said.

The findings in Washington raised concerns there could be similar problems in other transit systems across the country.

Transit networks with significant portions of their tracks underground will be the focus of the audit.

New York City’s MTA, Washington’s WMATA, Atlanta’s MARTA, San Francisco’s BART, Los Angeles’s MTA, Boston’s MBTA and Philadelphia’s SEPTA would be included.

In a letter, board members called on the Federal Transit Authority, a division of the Department of Transportation, to conduct the examination of tunnel ventilation systems as well as written emergency procedures for fire and smoke.

The FTA has not yet decided if it will investigate.

The agency said it “has not yet determined how an audit of this nature would be conducted or the potential impact such an audit would have on the transit riding public.”

Report a typo