By Selena Hill (staff@latinospost.com) | First Posted: Aug 02, 2013 02:51 PM EDT

A strike could shut down the San Francisco Bay area's commuter rail system by Monday morning. BART (Bay Area Rapid Transit) workers gave the California Bay Area transit agency a 72-hour notice on Thursday threatening to strike if a new labor deal isn't reached by a Sunday midnight deadline.

Union leaders made the announcement as a courtesy to the more than 400,000 San Francisco Bay area riders who would be forced to find alternative means of transportation if a strike is called.

The unions went on strike early in July, shutting down BART service for four days. As a result, commuters faced long lines for buses and ferries, and roadways were jammed. The strike ended after unions were granted a 30-day contract extension that is set to expire on Aug. 4.

"It is unfortunate that we find ourselves in the same situation that we were in 30 days ago, with no real progress made by management to address worker concerns about safety and wage cuts," said the president of the SEIU Local 1021, Roxanne Sanchez, one of two unions in talks with BART, according to NBC.

"This is not something that we want to do. This is not something that we intend to do," said Antonette Bryant, president of the Amalgamated Transit Union Local 1555.

The unions, which represent nearly 2,400 train operators, station agents, mechanics, maintenance workers and professional staff, are requesting a 5 percent raise each year over the next three years. However, BART said union train operators and station agents average about $71,000 in base salary and $11,000 in overtime annually. BART says it needs to save money on benefits to help pay for system improvements.

The two sides negotiated Thursday but did not appear close to an agreement.

BART spokesman Rick Rice said the agency was disappointed by the union's threats to go on strike.

"A strike only stalls and delays the decisions that need to be made while using our riders as pawns," he said in a statement, reports the AP. "BART is willing to stay at the table for as long as it takes to reach an agreement. Even if there isn't a deal in place by Sunday night, talks can be extended."

BART is the nation's fifth-largest rail system and carries passengers from the farthest reaches of San Francisco's densely populated eastern suburbs across the bay, through the city, and to San Francisco International Airport.

In case of a strike, BART plans to hire 95 charter buses to transport Bay Area commuters.

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