A Hyattsville woman died yesterday morning after her car plunged into the Tidal Basin and attempts to rescue her failed.

Police, firefighters and civilians dove into the chilly water and tried unsucessfully to pull the woman, identified as 43-year-old Mae Clark Richardson, from her locked car.

She was pronounced dead at Washington Hospital Center at 9:47 a.m. D.C. police called the death an apparent suicide.

The car driven by Richardson, of 2733 Nicholson St., apparently veered off West Basin Drive, went through a small stand of trees, over the seawall and into 15 feet of water, according to Sandra Alley, spokeswoman for the Park Service.

"I looked up from the manhole where we were working and there was this car just sitting in the water," said David Harrison, 39, a Pepco mechanic. "I grabbed the rope from off the truck and I ran over there. I got there and this man had already jumped in."

Harrison said the unidentifed man knocked on the car window and tried to open the door, which he later said was locked.

"We could see her sitting there in the car and she wasn't moving," Harrison said. "We didn't have any equipment to work with but we were going to try and save her. I threw the guy my rope and we tied the car to the seawall."

Harrison said that eight men who had gathered at the scene tried to pull the car toward the wall, but the rope broke.

Alley said that U.S. Park Police Sgt. Russell Walkowich also jumped into the water to try and break out a car window, which he was unable to do. Then the car turned over and went under water.

Acting Lt. Philip Pestone of the fire department rescue squad arrived shortly afterward and jumped into the water, along with another firefighter. He said he felt there was a good chance the woman was still alive, even though the car was submerged. But it took several dives just to locate the car in the murky water, he said.

"When we found the car, the door was slightly open and we were able to get our hands inside and then squeeze into the car," he said. They pulled Richardson out of the car, and she was taken to Washington Hospital Center by helicopter. She was alone in the car.

Later in the morning, as the late-model Chevrolet was pulled from the Tidal Basin by a tow truck, WJLA-TV (channel 7) cameraman Bill McDougall was knocked down by a Park Police officer while attempting to film the scene, according to witnesses and WJLA executive news director Tom Doerr.

"We have filed a protest with the Park Police and we are asurred that they are investigating the situation," said Doerr.

Park Police Maj. Richard Cusick, who identified the officer as Thomas Wood, said a "management review" of the incident is being conducted.

In a separate incident later yesterday, an unidentified man jumped into the Potomac River from the Memorial Bridge, according to Alley. She said the man survived.