The worker, believed to be about 20, and another man were taking apart an old rooftop water tank about 4 p.m. on a building near Grand and Sacramento, Fire Media Affairs Director Larry Langford said.
Crews have begun removing an iconic water tower on top of a museum in Andersonville, after it was damaged by the extreme cold this winter.
Lauren Hussar, 27, and Jack Baginski, 29, seek unspecified damages in the complaint filed Friday.
One of the three people injured when a wooden water tank fell nine stories on Wednesday has been released from the hospital.
Three people were hurt — one critically — when a water tank fell into an alley in the Lakeview neighborhood, sending water and debris flying.