One construction worker suffered a leg injury after an accident on the third floor of the Mars Bar building at around 1:45 p.m.

A battalion chief with the Fire Department, Bob Sputch, said that the worker was removing a piece of ceiling when a beam collapsed, possibly breaking the worker’s leg. Several witnesses at the corner of Second Avenue and First Street said that the injury did not appear to be serious.

“If you’d heard the bang, you would have thought it was something serious. But I think he’s alright,” said Malik Johnson, a construction worker at the site.

A neighbor lingering at the scene — who did not wish to give her name — said that she had complained to the Department of Buildings several times regarding improper removal of asbestos from the work site, as well demolition of a roof without work permits.

Since the revered Mars Bar closed in July, locals have kept a close eye on its impending destruction.

Mr. Johnson said that the dive is still standing.