The Associated Press

WEST MEMPHIS, Ark. — A heater that was not properly ventilated filled a daycare center with poisonous carbon monoxide gas Friday, forcing the evacuation of 22 children and eight adults, officials said.

Two of the children suffered seizures and three vomited after exposure to the gas. Four more showed signs of nausea and others were drowsy — all symptoms of carbon monoxide poisoning, said Assistant Fire Chief Eddie Spears.

The children and workers at Kids Child Care Center were treated and released from a hospital. Tests showed air in the building had high levels of carbon monoxide, which probably came from the heater, Spears said.