CHICAGO — Chicago fire officials sent out a “mayday” call today after firefighters became trapped when a wall collapsed while they were fighting a blaze at an abandoned commercial building.

Fire Media Affairs Director Larry Langford confirmed that firefighters were unaccounted for at the scene on Chicago’s South Side and that rescue crews were working to save them.

Later, three people were pulled from the building and rushed to hospitals. Dozens of firefighters at the scene continued to dig through the rubble, apparently searching for someone else.

There’s no word yet on the firefighters’ conditions.