Hamilton, NJ – Firefighters evacuated the McCorristin Square senior apartments on Leonard Avenue Monday after carbon monoxide filled the building, officials said.

No residents were injured during the incident, which began at about 11 a.m. at the complex off Cedar Lane, but about 12 were evaluated at the scene, firefighters said.

A carbon monoxide alarm detected the potentially deadly gas, firefighters said.

Township Fire Chief Chris Tozzi said the part per million (PPM) readings fire companies were getting on their detectors was in the hundreds, a dangerous level, so the conducted a systematic search and evacuation of the complex.

Carbon monoxide exposure affects people differently, but consistent exposure to the gas at over 1,000 PPM results in death within hours.

Once the building was evacuated and all the residents safe, firefighters turnre over control to the complex’s construction office and a utility crew on scene working on the issue, Tozzi said.