Old Saybrook ― The search for two missing boaters at the mouth of the Connecticut River in Old Saybrook stretched into its fourth day on Thursday without success.

The two men are missing from a boat carrying nine people that crashed into a breakwater Monday evening on its way to Connecticut from Block Island. Police have identified the one confirmed fatality as 34-year-old Christopher Hallahan of Westbrook but have not released names of the missing boaters.

The operator of the boat remains hospitalized in critical condition.

Led by the state Department of Energy and Environmental Protection, the search is being conducted using underwater drones and with dive teams on boats equipped with side scanning radar, which is typically used to recover bodies from the water.

The Norwich Underwater Search & Rescue team, with members from the Taftville and Yantic fire departments, aided in the search on Thursday.