The incident happened in Mönchengladbach, near Düsseldorf, in North Rhine-Westphalia at the weekend, as a family and their friends celebrated together, RP Online reported.
At around midnight on Saturday, a guest had brought the charcoal grill from outside into the living room to provide some warmth because the heating in the house wasn't working.
When those celebrating, including four children between the ages of two and seven, went to sleep, the residual heat from the grill began spreading toxic gases.
The fire brigade's measurements of the gases in the morning revealed that the concentration of carbon monoxide (CO) in the house was so high that it was only possible to enter the house wearing breathing apparatus.
Fortunately, the 15-year-old daughter of the homeowners got up on Sunday morning in time to save everyone's lives, the fire brigade said later.
The girl woke up everyone in the house and found everyone was suffering from the same symptoms, including nausea, headaches and dizziness.
She ran to a neighbour who immediately alerted the fire brigade shortly after 9:15 a.m. on Sunday. Emergency services deployed vehicles and two rescue helicopters due to the large number of casualties.
The detached house was immediately evacuated. “All the people were still responsive and could stand on their feet,” said the emergency operations director.
Of the 12 people involved, two were slightly injured while the others were more severely affected. Two members of the group “showed extreme symptoms,” said the operations director.
According to police, the 28-year-old guest who brought the barbecue grill into the house is the most severely injured.
Several people were flown by rescue helicopters to Düsseldorf and Aachen, where they were placed in high pressure chambers, which force oxygen into the body. The others were also sent to hospitals.
“The people were very lucky,” said the fire chief. The 28-year-old guest, who brought the barbecue into the house, could now possibly face criminal charges for negligent bodily injury.
Not the only incident
The accident in Mönchengladbach was not the only carbon monoxide incident at the weekend in North Rhine-Westphalia.
A family in Gelsenkirchen suffered CO poisoning, which was likely due to a defective heating system.
Firefighters had found a 10-year-old boy unconscious in his parents' apartment on Saturday and had taken him together with his mother to a hospital with a high pressure chamber. Four other relatives also received medical treatment.
Measurements had shown a significantly increased CO concentration in the apartment.
It was initially unclear where the gas was coming from; however, the fire brigade reported that there were later indications of a defect in the heating system. The system was turned off and the house ventilated.
Meanwhile, a barbecue evening for a family in Münster on Friday also ended in several hospital visits.
The barbecue was on the balcony in front of the living room. Toxic carbon monoxide entered the apartment through the door and spread throughout the house.
Several residents complained of nausea and dizziness. A total of 9 people were taken to hospital for treatment.