The Big Bang Theory elevator doors locked on all four floors of the building became an unquestionable piece of the show’s DNA, yet there is a deeper backstory to the fixture.
The origin of the broken elevator was revealed in the season 3 episode, “The Ladder Implementation”. The episode then goes back to the year 2003 to show how Leonard (Jhonny Galecki) first visited the apartment building.
The episode revealed how Howard (Simon Helbert), Raj (Kunal Nayyar), Sheldon, and Leonard became a quartet of friends. Although perhaps the most important thing is how Leonard broke the elevator.
When Leonard, a character from The Big Bang Theory, first visited the apartment building, the elevator was still working. But shortly after moving in with Sheldon, he brought one of his experiments home.
Leonard made a mistake mixing the fuel, not adjusting his calculations according to the dimensions of the rocket. As a result, fuel began to smoke inside his casing unit, and detonation was almost assured.
Leonard tried to get the fuel out of the apartment, but Sheldon from The Big Bang Theory saved his life by placing the container inside the open elevator and closing the doors just in time before the fuel exploded.
As a result, the elevator broke down and stayed that way until it was finally fixed in The Big Bang Theory season 12 finale, Stockholm Syndrome.
The story of how the elevator broke revealed one of The Big Bang Theory’s greatest mysteries, but it also served as a reminder to Sheldon that despite his many, many quirks, he saved Leonard’s life and didn’t give him away. .