Cummings, GA-, Ken Stanford – Eight people were in serious but stable condition after suffering carbon monoxide poisoning while spending the night on a houseboat on Lake Lanier.

The Atlanta Journal-Constitution quotes Forsyth County Fire Department Investigator Steve Anderson as saying the eight were sleeping on one of several houseboats tied up near an island on Two Mile Creek Friday night.

Anderson says the boat apparently didn’t vent properly – and the generator had been running all night, resulting in the carbon monoxide poisoning.

He says they were taken to area hospitals Saturday morning.