MD-80 jet

American Airlines MD-80 jet sits on the tarmac as fire rescue workers check the passenger plane at Miami International Airport. (Alan Diaz / Associated Press)

American Airlines today disputed the account of a man who said his cousin died aboard a flight after she was twice refused oxygen by a flight attendant. He also claimed that medical devices, including two oxygen tanks, failed.

Struggling to breathe, passenger Carine Desir, who had heart disease, asked for oxygen, but was initially denied, her cousin said Sunday.

"Don't let me die," the cousin, Antonio Oliver, recalled Desir, 44, saying after the attendant allegedly refused at first to administer the oxygen Friday.

He said the flight attendant finally relented but various medical devices on the plane did not work, including two oxygen tanks that were found to be empty and what may have been a defibrillator that seemed to malfunction.

American Airlines confirmed Desir's death and said medical professionals had tried to save the woman.

Today, airline spokesman Charley Wilson said there were 12 oxygen tanks on the plane and the crew checked them before the flight took off to make sure they were working. He said at least two were used on Desir.

"American Airlines, after investigation, has determined that oxygen was administered on the aircraft, and it was working, and the defibrillator was applied as well," he said.

Wilson said he didn't know whether a flight attendant initially refused to administer oxygen to Desir.

Desir, of New York City, died of natural causes, medical examiner's office spokeswoman Ellen Borakove said Sunday.

Desir had complained of not feeling well and being very thirsty on the Friday flight home from Port-au-Prince, Haiti, after she ate a meal, according to Oliver, who was traveling with her and her brother, Joel Desir. A flight attendant gave her water, he said.

A few minutes later, Desir said she was having "trouble breathing" and asked for oxygen, but a flight attendant twice refused her request, Oliver said.

He said other passengers aboard Flight 896 became agitated over the situation, and the flight attendant, apparently after phone consultation with the cockpit, tried to administer oxygen from a portable tank and mask, but the tank was empty.

Oliver said two doctors and two nurses were aboard and tried to administer oxygen from a second tank, which also was empty.

Desir was placed on the floor, and a nurse tried CPR, Oliver said. A "box," possibly a defibrillator, also was applied but didn't function effectively, he said.

Oliver said he then asked for the plane to "land right away so I can get her to a hospital," and the pilot agreed to divert to Miami, 45 minutes away. But during that time Desir collapsed and died, Oliver said.

"Her last words were, 'I cannot breathe,"' he said.

Wilson said three flight attendants helped Desir, but "stepped back" after doctors and nurses on the flight began to help her.

"Our crew acted very admirably. They did what they were trained to do, and the equipment was working," he said.

Desir was pronounced dead by one of the doctors, Joel Shulkin, and the flight continued to John F. Kennedy International Airport, without stopping in Miami. The woman's body was moved to the floor of the first-class section and covered with a blanket, Oliver said.

Shulkin, through his attorney, Justin Nadeau, declined to comment on the incident.