This dramatic audio from Carrie Fisher's United Airlines flight records the pilot radioing in a medical emergency after the 'unresponsive' Star Wars actress suffered a massive heart attack.
Fisher was put in to intensive care on a ventilator after paramedics were able to find a pulse while trying to resuscitate her.
She was taken to Ronald Reagan UCLA Medical Center after the United Airlines flight she was on landed at LAX.
In the audio recording the pilot can be heard telling air traffic control that passengers on board were "assisting" with treating Fisher.
He said "they are working on her right now and we are going to have her seated in about two minutes."
Passengers performed CPR on the 60-year-old star after she went into cardiac arrest on the flight, TMZ reported.
The United Airlines plane landed shortly after noon local time at Los Angeles International Airport after an 11-hour flight.
Fisher was then rushed to a nearby hospital by paramedics.
The LAX Police Department has revealed officers responded to Terminal 7 around 12:15 p.m. - for a call of a female passenger in cardiac arrest.
On arrival, they found paramedics performing CPR on the victim, according to Officer Alicia Hernandez.
Actress Anna Akana was on board the flight when Fisher went into medical distress and she described the upsetting scene in a series of tweets.
She said Fisher stopped breathing and was helped by a doctor and nurse who happened to be on board.
A United Airlines spokesperson said: "Medical personnel met United flight 935 from London to Los Angeles upon arrival today after the crew reported that a passenger was unresponsive.
"Our thoughts are with our customer at this time and any requests for additional information should be directed to local authorities."
Akana, 27, wrote: "Don't know how else to process this but Carrie Fisher stopped breathing on the flight home. Hope she's gonna be OK.
"So many thanks to the United flight crew who jumped into action, and the awesome doctor and nurse passengers who helped."
Akana wrote that Fisher wasn't breathing "for 10 minutes or so" and CPR was administered until the plane landed.
A United Airlines spokesperson said: "Medical personnel met United flight 935 from London to Los Angeles upon arrival today after the crew reported that a passenger was unresponsive."
Fisher has been travelling the world to promote her new book, the Princess Diarist, and posted a number of photos during her visit to the UK.
In her most recent tweet she posed for a photo outside Charles Dickens Lounge.
While in London Fisher recorded an appearance on the Graham Norton Show on December 7 and met fans as she promoted her book on December 11.
She became a global star after portraying Princess Leia in Star Wars and recently reprised the role in the series' two most recent films.
Devastated fans expressed their shock and sadness on social media, and offered prayers and thoughts for the actress.