This victory was soon followed by a costly defeat. Fort Niagara, one of the most important western forts, was not assaulted, but on September 14, 1763, at least 300 Senecas, Ottawas, and Ojibwas attacked a supply train along the Niagara Falls portage. Two companies sent from Fort Niagara to rescue the supply train were also defeated. More than 70 soldiers and teamsters were killed in these actions, which Anglo-Americans called the "Devil's Hole Massacre", the deadliest engagement for British soldiers during the war.