VANCOUVER, British Columbia — Five people died after a whale watching boat with 27 people on board sank off Vancouver Island on Sunday and one person remained missing, Canadian authorities said.

The vessel made a mayday call late Sunday afternoon on what was a calm, clear and sunny day off the tourist community of Tofino, a popular destination for whale watchers on Canada’s West Coast, the Joint Rescue Coordination Centre said.

The agency’s search concluded with five people dead, 21 rescued and one person missing.