The Grant Building in downtown Pittsburgh has been spelling out the city’s name in Morse Code via a flashing red light on the top of the structure since 1929. Except that a local grad student recently decoded the message to spell out “PITETSBKRRH” instead.

The building’s owners don’t know how long the message has been flashing incorrectly “or how and when the lights might be reset,” but they’re at least aware of the problem now.

The mistake was spotted by Tom Stepleton, 29, “while waiting to see the city’s Fourth of July fireworks show.”

[Pittsburgh Post-Gazette via The Register]