Firefighters on Wednesday night were working on repairing a broken water main inside an Uptown high rise.
The rupture happened at a senior apartment building in the 4900 block of North Sheridan Road. A fire official said there was up to five feet of water in the basement.
Commonwealth Edison crews switched the building over to generator power as a precaution.
"All systems are working inside the building and at this time we have elevator service. We have no reports of any injuries," said 2nd District Fire Chief Jeff Horan.
An evacuation of the 22-story building was not needed.