The family had gathered at Nieuwpoort to celebrate Christmas in an apartment that they had rented on the seafront. During the course of Christmas Eve several relatives started to feel poorly. The emergency services were alerted and the fire brigade took all nine relatives to hospital as a precaution.
Fire-fighter Luc David told the Belgian press agency Belga: "A poorly functioning heating boiler is probably the cause. Three ambulances and a reanimation vehicle attended the scene with a view to taking the family to Veurne Hospital.
Nobody lost consciousness, but fire officers measured high carbon monoxide levels in the flat.