David Lander has died at the age of 73.

The Laverne & Shirley actor died on Friday at around 6:30 PM at Cedars-Sinai Medical Center in Los Angeles as a result of complications from multiple sclerosis.

He had battled the condition for 37 years.

His wife Kathy and their daughter, actress Natalie Lander, and her husband were by his bedside when he passed away, according to TMZ.

David had worked as the Goodwill Ambassador for the National Multiple Sclerosis Society in the US.

He was best known for playing Squiggy on the sitcom Laverne & Shirley from 1976 to 1983.

David Lander has died at the age of 73
David in a promo photo for Laverne & Shirley with Michael McKean, Penny Marshall and Cindy Williams

His sidekick Lenny, played by Michael McKean.

David and Michael met at Carnegie University in Pittsburgh where they developed the characters.

They also starred together in Steven Spielberg's 1941 and in Kurt Russell's Used Cars.

David and his wife Kathy

The duo also voiced penguin cousins Henry and Louie in the  animated TV series, Oswald.

David starred in a number of TV shows and films, including The Bob Newhart Show, Barney Miller, Happy Days, Viva Valdez, Married... with Children, Twin Peaks, On the Air, The Weird Al Show, Mad About You, Pacific Blue, and The Drew Carey Show.

He married actress Kathy Fields in 1979.

David and Kathy with their daughter Natalie

Kathy worked as an actress and starred in Johnny Got His Gun, but later worked as as a professional photographer.

Their daughter Natalie, born in 1983, is also an actress who is known for her role in ABC's The Middle.

David was diagnosed with multiple sclerosis in 1984 but didn't reveal this publicly until 1999.

David Lander and Michael McKean in 1979

His autobiography Fall Down Laughing: How Squiggy Caught Multiple Sclerosis and Didn't Tell Nobody also touched on his condition.

David said he had kept the diagnosis a secret when he got health checks before starting work on films and shows.

He tried everything to improve his condition, including exercise, alternative medicine, support groups and medication.

David had battled multiple sclerosis for 37 years

When he shared his diagnosis publicly, David said: "I just figured that if people can see me, and see that I'm working - I guess I call it 'fighting' M.S. - maybe I can do some good."

He added: "The first two years were the toughest. I've been in remission most of the past 13 years.

"The major way it affects me is called 'drop foot' in which my knee will buckle. I have to go down stairs slowly, holding the railing, but so do a lot of people who don't have M.S."