CANTON (CBS) – A mother, father, and their son have all been rushed to the hospital after being overcome by carbon monoxide in their home.

Canton Fire Chief Charles Doody told WBZ NewsRadio 1030’s Karen Twomey that the husband called 911 early this morning, concerned that he couldn’t wake up his wife.

WBZ NewsRadio 1030′s Karen Twomey reports.

Firefighters found dangerously high levels of carbon monoxide when they arrived at the home.

The three victims were rushed to Massachusetts General Hospital, where they are being treated in hyperbaric chambers.

The mom is said to be in serious condition. The dad and son are expected to be okay.

Chief Doody says firefighters were quickly able to figure out the source of the potentially lethal gas.

“In this case, it was actually a motor vehicle that was running in the garage underneath the house,” he said.

WBZ-TV’s Kate Merrill reports.

The chief says the car had been running all night. The home did not have carbon monoxide detectors.

As of right now, investigators are treating the incident as accidental.