Canada's worst known geophysical disaster came from the Tseax Cone during the 18th century at the southernmost end of the volcanic belt. The eruption produced a 22.5-km-long lava flow, destroying the Nisga'a villages and the death of at least 2000 Nisga'a people by volcanic gases and poisonous smoke. The Nass River valley was inundated by the lava flows and contains abundant tree molds and lava tubes. The event happened at the same time as the arrival of the first European explorers to penetrate the uncharted coastal waters of northern British Columbia. Today, the basaltic lava deposits are a draw to tourists and are part of the Nisga'a Memorial Lava Beds Provincial Park.