ATLANTA - Flight attendants discovered the body of a 61-year-old woman in the restroom of a plane shortly before the flight landed in Atlanta Wednesday morning, a spokeswoman for the airline said.

It was unclear how Michaele O'Neil Carnahan died, and how long she was in the restroom.

The crew on the Los Angeles-to-Atlanta flight noticed the restroom was occupied on final approach, just before Flight 950 touched down at Hartsfield-Jackson Atlanta International Airport at 5:51 a.m., spokeswoman Keyra Johnson said. Atlanta police were notified and met the plane at the gate, Johnson said.

"Delta extends its condolences to the family and commends our flight crew and medical professionals onboard who handled this incident with the utmost professionalism and respect for which they are known," spokeswoman Betsy Talton wrote in an e-mail.

The body was taken to the Georgia Bureau of Investigation Crime Lab in suburban Atlanta for an autopsy scheduled for Thursday, said GBI spokesman John Bankhead. Authorities were awaiting the results to determine the cause of death, Bankhead said.

Bankhead said Carnahan was on her way from her home in Ventura, Calif., to Florida for a wedding.

Atlanta police stationed at the airport respond to calls about dead bodies on airplanes a couple of times a year, said Officer Eric Schwartz, a police spokesman. Talton said the situation was rare, but flight crews are trained to handle "a number of situations on board."

Airlines are not required to track or report the medical incidents they handle, so an exact tally of in-flight deaths is hard to determine. MedAire, an Arizona-based company that staffs doctors on the ground to advise flight crews in a medical emergency, counted 89 deaths for the flights they handled in 2006, which represents about one-third of the world's commercial flights.

If the death rate is similar for the rest of the flights, annual deaths on airplanes could exceed 260.