Bay Area residents were without commuter rail service and facing a morning of frustration Friday as BART workers went on strike after a week of marathon negotiation collapsed overnight.

Plans were in place for enhanced bus and ferry service, as well as expanded carpool hours, but those measures were not expected to come close to satisfying demand.

As negotiations between Bay Area Rapid Transit management and the leaders of Service Employees International Union Local 1021 and Amalgamated Transit Union Local 1555 crumbled late Thursday, BART riders were already venting their frustration.

“They must realize how many thousands, hundreds of thousands of people they’re throwing into chaos," J.D. Trow told KCRA-TV.

Despite both sides making concessions on numerous issues -- including health benefit and pension contributions -- talks broke down over overtime scheduling and how to manage pay stubs for workers, local media reported.

The strike is the second BART work stoppage in four months, and comes after Gov. Jerry Brown stepped in with a 60-day cooling-off period as the latest labor dispute heated up.

Beyond the toll on commuters, the strike was expected to hit the area's economy hard. The Bay Area Council, a regional business organization, calculated the costs of BART’s 4 1/2-day strike in July at $73 million a day.

BART typically carries 400,000 riders each workday.

"It’s going to be catastrophic,” said Rufus Jeffris, a spokesman for council.

As news of the strike emerged late Thursday, both sides at the negotiating table engaged in a round of finger-pointing.

Antonette Bryant, president of ATU Local 1555, placed the blame squarely on BART management.

“This is not a union strike, this is a management strike, brought on by arrogance," she said.

In her own news conference, BART General Manager Grace Crunican said management had offered a good deal to workers, and she urged the unions to take it to a vote.

“It’s not management that called for a strike, it’s the unions,” she said.

Riders were expressing disappointment in both sides Thursday night as they scrambled to make contingency plans for Friday morning.

“I think that after these several rounds of negotiations, you’d hope that they’d made a little more progress at this point," Joshua Gresham told KCRA.

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Twitter: @leeromney

lee.romney@latimes.com