Happy 40th Birthday, ‘Laverne & Shirley’!

40 years ago today, Penny Marshall and Cindy Williams schlemiel-schlamazeled their way into TV history when “Laverne & Shirley” premiered on ABC.

Laverne DeFazio and Shirley Feeney, two roommates who worked as bottle-cappers in Milwaukee, had made their debut on “Happy Days” the November before their own spin-off started airing on January 27, 1976. The zany antics of “Laverne & Shirley” quickly shot to No. 1 in the ratings, even surpassing the viewership of “Happy Days.”

Williams departed the show after she became pregnant with her first child. As to why she left instead of scheduling around the birth of her baby, Williams has said, “When it came time for me to sign my contract for that season, they had me working on my due date to have my baby. And I said, ‘You know, I can't sign this.” And it went back and forth and back and forth and it just never got worked out.” Marshall wrapped up the eighth and final season of “Laverne & Shirley” without Williams.

Marshall and Williams also voiced their iconic characters in the animated series “Laverne & Shirley in the Army,” which lasted for 13 episodes. The duo reunited in 2013 for an episode of Nickelodeon show “Sam & Cat.”

Other notable January 27 happenings in pop culture history:

• 1926: The first public demonstration of a television system was held in London.

• 1956: Elvis Presley”s single “Heartbreak Hotel” was released.

• 1968: The Bee Gees made their American debut at the Convention Center in Anaheim, California.

• 1970: John Lennon wrote and recorded “Instant Karma” all in one day and released it 13 days later.

• 1984: Cyndi Lauper”s “Time After Time” single was released. Also on that day, John Lennon and Yoko Ono album “Milk and Honey” hit record store shelves the U.S.

• 1984: Michael Jackson”s scalp was burned in a special effects-gone-wrong accident while filming a Pepsi commercial in Los Angeles. He was singing “Billie Jean” for the ad when a fireworks display erupted behind him and set fire to his hair.