UPDATED 9:50 p.m. ET 

Star Wars royalty Carrie Fisher is in the intensive care unit following a heart attack Friday, Fisher's brother Todd told the Associated Press. Todd had previously said Fisher was "out of emergency" but later said information about what caused the cardiac arrest and information about her condition were unknown. 

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Carrie Fisher is in critical condition after she suffered a "massive heart attack" Friday while on a plane according to the Los Angeles Times. Fisher was on a flight from London to Los Angeles when she went into cardiac arrest, TMZ reported. CPR was administered by people on board before the plane landed at LAX. Fisher was then transported to a hospital by Los Angeles Fire Department paramedics. Fisher is at UCLA Medical Center on a ventilator.

The emergency took place approximately 15 minutes before the plane was scheduled to land, TMZ reported. Once a flight attendant asked if any medical personnel were on the plane and could offer assistance, an EMT from the back of the plane "came up to first class and administered life-saving measures." The LAX Police Department said officers responded to a call of female passenger in cardiac arrest at around 12:15 p.m. Officer Alicia Hernandez said paramedics were performing CPR on Fisher when officers arrived on the scene. CPR was performed on Fisher for 15 minutes before paramedics got a pulse TMZ reported.

The Star Wars icon has been touring in promotion of her recently released book, a memoir entitled The Princess Diarist. Speaking with Rolling Stone surrounding the book's release last month, Fisher opened up about the impact her Star Wars role had on her life and career. "It's sort of the engine that pushed everything else through," she said. "I would have been a writer, though. I didn't really mean to be an actress. But if your second movie is Star Wars, you're done. You're gonna be pursuing that because otherwise it'll pursue you."

Following Friday's news, fans and friends alike shared their well wishes for Fisher:

This story is developing.