Mark Madrigal

BART station agent Mark Madrigal stands next to his booth at the Lake Merritt station in Oakland. (Marcio Jose Sanchez / Associated Press / June 28, 2013)

Workers in two of Bay Area Rapid Transit's largest unions were on strike Monday morning, halting service for an estimated 400,000 passengers who use the nation's fifth-largest rail system each weekday.

SEIU Local 1021 spokeswoman Cecille Isidro said workers began their strike across the Bay Area around 2 a.m. Monday after the final trains were put to bed.

From a picket line at the Lake Merritt station in Oakland, she said the union expects that a majority of workers will take part in the strike.

“BART management threw in the towel tonight and pushed away from the bargaining table hours before the expiration of union contracts," SEIU Local 1021 said in a statement.

In anticipation of a strike late Sunday, transit officials urged commuters to use BART.gov and 511.org to find alternate ways to get to work.

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