Gas leak at Four Seasons Hotel prompts hazmat response

CHICAGO (WLS) -- A gas leak occurred at a luxury hotel in Chicago's Gold Coast neighborhood overnight.

Chicago firefighters responded to the Four Seasons Hotel at 120 East Delaware Place just before 3 a.m. Monday after a chlorine tank began to leak.

Chief Michael Fox of the Chicago Fire Department said crews called for a Level 2 hazmat and EMS Plan 1 response. There was a small explosion on the seventh floor. No one was hurt.

"They were mixing up a new batch of chlorine to put into the swimming pool and the hot tub. There was a small explosion, which let the chlorine go onto the floor of the operating room for the pool maintenance - for the pumps and everything. At this time we don't know what caused the explosion, but we're pumping out the chlorine tank right now," Fox said.

The hotel was not evacuated, but employees working on the seventh floor left the area. They were seen wearing masks near the front door of the hotel.

Firefighters asked people to stay in their rooms, but to call 911 if they experienced any problems. Floors 9-20 at the Four Seasons are commercial. Floors 20 and up are residential.

Fox said the chlorine leak was contained to one room on the seventh floor. Crews were wrapping up around 5:30 a.m.