Prince George's County police says four family members are in critical condition after being exposed to high levels of carbon monoxide in their home.
Police say the family was found unconscious in the 8300 block of Bernard Drive in Fort Washington about 12:30 a.m. Tuesday.
On Monday evening, one of the children in the family fell off the bed and to the floor unconscious. The father rushed the child to Children's National Medical Center for treatment. After conducting blood tests, doctors realized the child had elevated levels of carbon monoxide, and had likely been poisoned at home.
The father called his family to warn them of the danger, but was unable to reach anyone there. He then called his brother, who ran to family's home to render help, and also called 911.
Emergency medical personnel showed up after midnight, pulling four unconscious family members from the home. Firefighters said the carbon monoxide gas measured in the air at 450 parts per million - a safe reading is 5 parts per million.
The four members inside the house were transported by helicopter to Baltimore for treatment. The father was also found to have elevated levels of CO in his bloodstream, and received treatment. Authorities said it was miraculous that he was able to drive his child to the hospital.
The source of the gas contamination has been traced to a malfunctioning natural gas heater in the basement.