Kansas University’s steam whistle, whose booming sound has signaled the end of classes on KU’s main campus in Lawrence for more than six decades, is down indefinitely for repairs, university officials say.

The whistle, located on top of the campus power plant on Sunflower Road, became detached after sounding at 9:20 a.m. Wednesday, said Doug Riat, director of KU facilities and operations.

The damage to the whistle was the result of recurring problems and not weather-related, Riat said. He said the whistle can’t be repaired and no decision has been made whether to replace it.