A fire broke out early Tuesday in a Loop high-rise, killing one pet and sending six people to hospitals for smoke inhalation.
The fire, possibly electrical in nature, was contained to a single unit on the 32nd floor in the 400 block of East Randolph Street, Chicago fire and police officials said.
Crews responded at 12:30 a.m. and extinguished the fire within an hour, fire officials said.
A couple in the affected unit, a woman, 69, and a man, 77, were hospitalized in serious condition at Stroger Hospital, according to police spokeswoman Sally Bown.
Four people in other units were taken to Northwestern Memorial Hospital in fair condition, Bown said. They included a man and woman, both 27, and two men, ages 46 and 76.
One pet died in the fire, a fire official said. The building was not evacuated.
The cause of the fire remains under investigation.