AUSTIN, TEX., JULY 30 -- Former representative Barbara Jordan (D-Tex.), who gained national prominence in 1974 during the impeachment hearings on President Richard M. Nixon, was in critical condition today after she was found floating unconscious in a swimming pool at her home, authorities said.

Officers had responded to a report of a possible drowning shortly after noon, and Jordan was treated at the scene by emergency medical technicians, said sheriff's Lt. Gary Irwin.

Jordan, 52, was taken by helicopter to Brackenridge Hospital in critical condition, authorities said. Paramedics "said she had a pulse, was trying to breathe and they were able to help her breathe en route to hospital," said hospital spokeswoman Carolyn Boyle.

Jordan was in intensive care this afternoon, Boyle said. Dr. Pat Crocker said she had suffered cardiac arrest and was being given medication to help clear fluid from her lungs.

"She is improving," Crocker said. "She is awake. It appears that there's been no damage of any kind to her brain. She's mouthing words around the tube" of the ventilator being used to help her breathe.

Jordan, who suffers from a degenerative bone disease and uses a wheelchair, was swimming alone, hospital officials said. Jordan for years has refused to discuss the illness, simply calling it "a mobility problem" and denying that it was Lou Gehrig's disease or bone cancer.

Nancy Earl, who lives with Jordan, returned from a short trip to a store, found Jordan floating in the pool and administered cardiopulmonary resuscitation until medics arrived, said Helen Tackett, a spokeswoman for the University of Texas, where Jordan is on the faculty.

Investigators have not yet determined how the accident happened.

The daughter of a Baptist minister, Jordan in 1966 became the first black state senator in Texas history. In 1972, she was the first Southern black elected to Congress since Reconstruction.

Jordan, once considered a possible Democratic vice presidential candidate, turned her back on politics after three terms in the House, choosing to teach at the University of Texas.

She addressed the recent Democratic National Convention in Atlanta and spoke in support of fellow Texan Sen. Lloyd Bentsen.