LOS ANGELES (Reuters) - Friends and colleagues of Hollywood actress Carrie Fisher shared their hopes for the “Star Wars” star’s swift recovery on Saturday, a day after she was admitted to the intensive care unit of a Los Angeles hospital.

Fisher, 60, suffered heart problems during a flight on Friday from London, where she had been shooting the third season of the British television comedy “Catastrophe.” Her younger brother, Todd Fisher, said she was taken to the hospital in critical condition and was undergoing treatment in the ICU.

No further details on her condition or prognosis were immediately available on Saturday, and a spokeswoman at the Ronald Reagan UCLA Medical Center declined to comment, citing patient confidentiality laws.

“I’m shocked and saddened to hear the news about my dear friend,” actor Harrison Ford told The Hollywood Reporter on Saturday. Ford played the swashbuckling Han Solo opposite Fisher’s Princess Leia in the original “Star Wars” film trilogy.

“Our thoughts are with Carrie, her family and friends.”

Fisher caused a stir in November with the disclosure that she had a love affair with Ford during the making of the first “Star Wars” movie. Fisher revealed the secret to People magazine while promoting her new memoir, “The Princess Diarist,” just before it went on sale.

Her friend William Shatner, best known for his role in the “Star Trek” television and film series, posted an old photograph on Twitter of him and Fisher embracing, writing that she was “all I want for Christmas.”

One of the more attention-grabbing messages appeared to come from Fisher’s dog Gary, who has his own Twitter account and was reported to be with her at the hospital.

“I’ll be waiting right here mommy,” Gary tweeted in a post with a photo of the French bulldog staring attentively through a window - ears perked, paws perched on the sill.

Other celebrities, including Ellen DeGeneres and Christina Applegate, took to social media to share their sadness, while the singer-actress Bette Midler described Fisher as “hilarious on paper and in person, and just plain beloved.”

Fisher reprised her “Star Wars” role in two sequels, gaining sex symbol status in 1983’s “Return of the Jedi” when the Leia character appeared, wearing a metallic gold bikini, as a captive of an evil alien.

She returned last year in Disney’s reboot of the “Star Wars” franchise, “The Force Awakens,” appearing as the more matronly military resistance leader, General Leia Organa.

Fisher’s career has been dogged at times by substance abuse and mental health issues, about which she has spoken openly.

Her bestselling novel “Postcards from the Edge,” based on her experience in drug rehab, was adapted into a 1990 movie starring Meryl Streep. Fisher has also said she was briefly hospitalized in 2013 due to bipolar disorder.