Six people who were aboard a charter boat that sank off the coast of B.C. Sunday are presumed drowned, according to authorities. The Richmond RCMP, which took over the case when a rescue operation was called off, provided the update in a statement Monday. “Despite extensive multi-agency search efforts conducted yesterday, four men and two women remain unaccounted for and are presumed drowned,” a spokesperson wrote. “The search has been suspended, and efforts have now shifted to recovery.” There were 10 people on board when the vessel capsized. Four were rescued with the help of a couple sailing in the area who pulled people from the water and made the mayday call that triggered the massive search effort. Of the four taken to hospital, two have been released. Two—a 33-year-old man and a 28-year-old woman—remain in critical condition, according to police. “The investigation remains ongoing to determine the cause of the sinking and to confirm the identities of the six missing individuals. Efforts are also underway to notify their respective next of kin,” the statement from the Richmond RCMP said. The RCMP’s Underwater Recovery Team is expected to arrive in the coming days and will assess the best way to recover the sunken boat. “The vessel is believed to have sunk in very deep waters,” Monday’s statement from Mounties said. The Transportation Safety Board and Transport Canada have also been notified and are co-ordinating with local agencies on the investigation and next steps.