At least five people died after a whale-watching boat sank off the coast of Tofino, a popular fishing town in west Canada, on Sunday afternoon. Helicopters, planes and boats managed to pick up 21 of the other passengers, but one person was still missing when rescue operations were suspended once darkness fell. The rescue work will resume after daybreak, The Guardian reported.

Tofino, located on Vancouver Island along the Pacific coast, is popular with tourists, who often go out on boating expeditions. Locals stepped in to help with the emergency efforts on Sunday, and the town’s mayor said the mood in the town remains tense. The weather on Sunday was clear and sunny, and it is unclear why the Leviathan II sank.