A 66-year-old retired naval officer who had lain immobile for as long as a day and a half after she had fallen down a flight of stairs, at her Foggy Bottom home, was rescued yesterday by D.C. police and was admitted to George Washington University Hospital in fair condition, officials reported.

Police said Lt. Comdr. Dorothy Z. Brewer (Ret.) of 828 25th St. NW suffered a concussion, fractured left arm, and back and neck injuries when she tripped over a second-floor carpet and fell down the staircase sometime Monday night.

Police said they were summoned to Brewer's house by neighbors who heard the woman's dog barking and discovered Tuesday mail in her mailbox and day-old newspapers still on her front steps.

Receiving no response to the front doorbell, 2nd District police Officer Mark Mahlman went to the backyard and heard Brewer moaning through an open window, police said.

"I'm trapped and can't get up," Brewer reportedly answered when Mahlman asked if she was all right.

After breaking open the front door police found the woman with her head trapped between an entryway bureau and the foot of the staircase. Police said Brewer's legs were positioned above her head on the stairs, and that she had lost blood from a head cut.

"I knew something was wrong because when I went over to her house yesterday to borrow some flowers, all I heard was the dog barking," said Martin Quinn, a neighbor.

"She runs a really tight ship, and just wasn't the kind of person to leave mail in the slot or old papers on the porch."