Lexington, KY – Lexington firefighters evacuated an apartment building, and a few residents were left a bit light-headed after a carbon monoxide buildup inside late Monday night.

Firefighters responded to the Pegasus Place Apartments on Larkin Road around 11:45 p.m. after someone called 911 when a CO alarm went off.

“We were just watching TV and heard the alarm go off in the neighboring apartment across the hall, then firefighters began to evacuate the building,” Hunter Fleming said.

Firefighters say they found a blockage in the building’s ventilation system that caused a buildup of the gas. Lexington Fire Department Maj. Jason Walton said early detection was the key to keeping everyone safe.

“This is why it’s so important to have CO detectors in homes with gas appliances. Without that, this could’ve gone a lot worse,” he said.

Residents were kept outside for about 90 minutes as firefighters ventilated the building. A few people reported headaches, but nobody was hospitalized.