Former U.S. Rep. Barbara Jordan, who rose to fame in 1974 during the Watergate impeachment hearings, was in critical condition Saturday after she was found floating unconscious in a swimming pool at her home, authorities said.

Law 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, who suffers from a degenerative bone disease and uses a wheelchair, was swimming alone, hospital officials said. A witness told authorities she was found floating in the pool.

"They kept her at the scene before transporting her to ensure they got her stabilized," Irwin said, adding that Jordan's pulse and respiration were restored. "EMS technicians stabilized her, then transported her by Starflight (helicopter) to Brackenridge Hospital."

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.

She was a protege of President Lyndon Johnson and gained a national reputation during the House Judiciary Committee's 1974 hearings that ended with a vote to press impeachment charges against President Richard Nixon.