Dayton, OH- Three people were taken to the hospital, with one in critical condition, according to Captain Andy Wiley with the Dayton Fire Department.

The occupants of the home were running a generator in the basement.

Two of the occupants were outside when medics arrived, and the third was found inside nearly unconscious, Wiley said.

Wiley said they had been running a generator on the front porch but it was stolen, so they put one in the basement. They had installed a “makeshift ventilation system down there,” but it didn’t work and carbon monoxide levels quickly climbed, he said.

Several cats and dogs also were rescued from the scene, but none had been found in poor shape yet, Wiley said.