Carrie Fisher is in stable condition after suffering a major heart attack on a flight, the Associated Press reports.

Fisher, 60, was aboard an 11-hour flight from London to Los Angeles on Friday when she went into cardiac arrest. After the plane landed just after noon in California, Fisher was spotted being rushed to the hospital.

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Todd Fisher, the actress’ brother, told the AP that his sister was “out of emergency” and stabilized at a Los Angeles hospital, but declined to offer further details.

Also on Friday, Todd told Entertainment Tonight that Carrie’s condition is still unknown. “She is in the intensive care unit, she is being well looked after,” he said. “If everyone could just pray for her that would be good. The doctors are doing their thing and we don’t want to bug them. We are waiting by patiently.”

Adding, “We don’t know. We hope for the best. We certainly do not know her condition, that’s why she is in ICU. I’m sure everyone wants to speculate, but now is not the time for that.”

In a phone interview, Todd explained to Variety: “Everybody’s praying for her. There’s nothing new from the doctors … There’s no good news or bad news.”

The Los Angeles Times had previously reported that Fisher was in critical condition. Her daughter Billie Lourd and beloved dog Gary were spotted at the hospital on Friday, according to TMZ. The news outlet also reports that Fisher is reportedly on a ventilator.

The Los Angeles Fire Department tells PEOPLE that a patient was “aggressively treated” after suffering from cardiac arrest on an inbound flight to LAX, although they would not confirm the name of the patient. She has been rushed to a Los Angeles-area hospital.

A United spokesperson confirmed to PEOPLE that a passenger was unresponsive when the plane arrived in LAX.

“Medical personnel met United flight 935 from London to Los Angeles upon arrival today after the crew reported that a passenger was unresponsive,” the spokesperson said in a statement. “Our thoughts are with our customer at this time and any requests for additional information should be directed to local authorities.”

An LAX airport onlooker tells PEOPLE she spotted emergency workers assisting Fisher after they got her off the plane in the United terminal.

“It was scary. There was a team of about six emergency workers pushing her out in a stretcher. She had an oxygen mask on and they were yelling at people to get out of the way as they pushed her through,” says the witness.

Actress Anna Akana claimed on Twitter that she witnessed Fisher’s health emergency, writing, “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,” she added. “Feel weird even tweeting about it but I JUST finished her book and was fangirling out over seeing her dog Gary in person. Gah.”

Comedian Brad Gage wrote on the social media site that he was traveling with Akana, noting that Fisher was allegedly “taken off the plane by EMTs.” Akana responded that Fisher “wasn’t breathing for 10 minutes or so.”

The actress has been in London filming the U.K. sitcom Catastrophe. Costar and co-creator Sharon Horgan shared an image of the duo on Instagram last week, captioning the playful photo “me, General Leia and Kylo Ren’s hand on the set of #catastrophe3.

She was last photographed leaving celebrity hot spot the Chiltern Firehouse in London on Dec. 15.

Image zoom MelMedia/GC Images

After news broke, former costars and friends took to social media to send their prayers and best wishes to the iconic star.

Fisher recently published a memoir, The Princess Diarist, about her time on the set of the iconic first Star Wars film.

She previously starred in an autobiographical one-woman show, Wishful Drinking, that was also turned into a book and HBO special. It details her past struggles with alcohol and drugs including LSD, pills and cocaine. She has also been open about her bipolar disorder diagnosis.

“I used to think I was a drug addict, pure and simple — just someone who could not stop taking drugs willfully,” Fisher once told Diane Sawyer. “And I was that. But it turns out that I am severely manic depressive.”

Fisher’s addiction was also largely profiled in her 1987 best-selling, semi-autobiographical novel Postcards from the Edge, which was later turned into a movie starring Meryl Streep.

The actress shares one daughter, actress Billie Lourd, with ex Bryan Lourd.

TMZ was first to report the news.