The Democratic National Convention, which starts Monday, will bring 20,000 delegates and visitors, almost as many journalists and thousands of protesters to the Staples Center, the site of the four-day meeting that will nominate Al Gore for president.

Hoping to avoid the crowds and traffic restrictions, most city utilities plan to postpone routine work in the largely commercial area around the sports arena. Meantime, federal agents have asked hospitals to prepare for possible chemical and biological terrorist attacks during the event.

"The big concerns are that terrorists will try to use bioterrorism to attack the area," said Jim Lott, executive vice president of the Healthcare Association of Southern California, which represents hospitals in Los Angeles County.

Nearly a dozen hospitals near the Staples Center have stocked up on antidotes and undergone decontamination training, he said. They also have bought protective equipment that could shield the staff from toxins.

The likelihood of such an attack is uncertain; one has never occurred in the United States. But the FBI, Secret Service and police say having President Clinton, Vice President Gore and thousands of Democratic Party activists, protesters and media in one place makes the city a target.

Lott would not say which biochemicals the hospitals have prepared to handle.

The city fire department, which also runs ambulance service through Los Angeles, has suspended most routine fire safety inspections to free workers usually assigned to those duties.

The extra emergency staffing adds the equivalent of 30 more companies to the department's current 228 companies, Battalion Chief Daryl Arbuthnott said.

"We're not robbing services from other parts of the city unless something significant breaks out," he said. "If that happens, we have mutual aid agreements with fire departments in surrounding communities to help us out."

Bob Canfield, an emergency preparedness analyst for Los Angeles, said residents shouldn't worry about the city shutting down during the convention.

"L.A. is a big city, 470 square miles, and there will be a lot of places you can go during the Democratic Convention and not even know something's going on," he said. "Those places will still be clamoring for regular city services, and the city will function normally."

The only area to be significantly affected will by the event will be the downtown neighborhood surrounding the Staples Center, Canfield speculated.

Meter-readers and maintenance crews with the Los Angeles Department of Water and Power will avoid the downtown unless there is an emergency, said agency spokesman Randy Howard.

The Metropolitan Transportation Authority has diverted buses around arena to avoid convention congestion, said agency spokesman Jose Ubaldo. He said commuters should expect 15- to 20-minute delays on routes that usually travel near Staples Center.

Older buses ready for retirement will be returned to the streets during the week to compensate for the nearly 100 buses the department has rented to convention planners to transport delegates, Ubaldo said.

MTA officials have also increased security on its rail system, fearing trains could be a target for terrorists or unruly protesters.

The Department of Water and Power also has placed extra security at potential terrorist targets, such as reservoirs and major power facilities, Howard said.