Passaic, NJ – Authorities say a 23-year-old northern New Jersey mom and her year-old son died of carbon monoxide poisoning while sitting in a running car that had its tailpipe covered in snow.

Passaic police say the woman’s 3-year-old daughter was also hurt and is hospitalized in “very critical condition.”

Authorities found the three when they responded to a Sherman Street location around 8:15 p.m. Saturday. The woman’s husband had been shoveling snow for about 20 minutes and when he returned to the car, he found his family unresponsive.

Residents performed CPR on the three victims before they were taken to a hospital, where the mother and her son were pronounced dead a short time later. Their names have not been released.

No other injuries were reported in the incident.