SAN FRANCISCO -- A raucous display by union members outside a high-end hotel in San Francisco’s Union Square led some guests to find another place to stay as hundreds of workers dug in for the first day of a three-day strike.

The vocal crowds were picketing the Grand Hyatt to make a point to management about contract talks that union officials said have reached an impasse. Union members voted Wednesday night to start the three-day strike, which is scheduled to end Sunday morning.

About 340 employees including housekeepers, bellmen, doormen and restaurant workers joined the picket line Thursday morning. Leaders said they are trying to make a point to management about contract talks that have hit an impasse.

"I feel very sad, because we work very hard for them and they don't feel the same about us," said striking hotel worker Erika Rosales.

Hotel manager David Nadelman said he was stunned by the union calling striking after five bargaining sessions. He the last discussion was Wednesday.

Union leaders said they chose to strike Thursday to coincide with the IPO of the hotel's parent company going public on the New York Stock Exchange.

"One family makes a billion dollars on the stock market in one day. 300 families have to strike in order to just preserve their health care at a cost of $250,000 a year," said Local 2 President Mike Casey.

At issue are healthcare benefits and the length of a contract.

The union wants a one-year deal, so it can negotiate as the economy improves. Hotel management wants a five-year contract. There's been no contract since mid-August.

Managers from other Hyatt hotels have stepped in to replace the striking workers.

The strike has had one immediate impact. Several guests said the striking workers woke them up Thursday morning. One man told KTVU he asked to be moved to another room and at least one couple decided to find another hotel.

Union leaders and hotel management said negotiations will resume next Thursday.