Nine people, including four children, were sent to hospitals early Thursday after carbon monoxide was detected in a building in Austin on the West Side.

Firefighters responded to the high carbon monoxide reading about 3 a.m. to the 600 block of North Lockwood Avenue, according to Chicago Fire Media Affairs.

Four children and five adults were transported to hospitals, the department said. Their conditions had stabilized.

Peoples Gas was at the scene, according to the department. Additional information was not released.