Somerville, MA- Just after 8 p.m. Sunday night (Feb. 24), Chief 2, Engine 1 and Ladder 2 responded to 23 Stickney Ave. for a carbon monoxide alarm.

Firefighters determined the carbon monoxide levels to be at 750 ppm.

Somerville Fire Department Lieutenant Thomas Salemme said those levels were lethal and if the Fire Department had not responded, everyone in the building would have died. The property’s owner, two of her children and a tenant were transported to Massachusetts General Hospital via EMS for treatment.

“It is a lethal dosage over a certain period of time,” Salemme said.

Chief Pete St. Clair said a 45 minute exposure to that amount of carbon monoxide produces dizziness and headaches, but if anyone was exposed to it for 4 hours they would be killed. Firefighters said they did not know how long the family was exposed to it.

“The carbon monoxide detector should have gone off at 35 ppm,” St. Clair said. “They were in danger of serious effects if they hadn’t evacuated.”

According to Salemme, an acceptable level of carbon monoxide in a home is 15 ppm over the course of 8 hours. “If you have 1,000 ppm over thirty minutes,” says an internal Fire Department training handout, “it puts you at a high level of danger in the form of collapse into a coma or permanent brain damage.” Keyspan was also on scene.

After the injured parties were transported, firefighters vented the property.