David Lander, the actor famous for playing Squiggy on the hit show Laverne & Shirley, has died from complications due to multiple sclerosis. He was 73. Lander was born in Brooklyn, New York and studied acting at NYU and Carnegie Mellon in Pittsburgh, where he met his acting partner Michael McKean, who would go on to play Lenny alongside Lander in Laverne & Shirley. Lander and McKean were originally hired as writers on the show, but producers quickly decided to cast them as the main characters’ goofy neighbors and friends. Lander also played a taxidermist in Twin Peaks and appeared alongside McKean in Steven Spielberg’s film 1941, among other roles.

He was diagnosed with multiple sclerosis more than 30 years ago, although he didn’t publicly share his diagnosis until 1999. He then became an ambassador for the Multiple Sclerosis Society and published a book, Fall Down Laughing: How Squiggy Caught Multiple Sclerosis and Didn’t Tell Nobody in 2000. He died Friday around 6:30 p.m. at Cedars-Sinai Medical Center in Los Angeles, according to TMZ.