Update
Just seen a video of this on ABC news last night. Its increadable that anyone got out . The front of the Jayhawk is completely smashed. High seas and very cold water (news said 28 deg f?) . They were amazingly lucky that a second jayhawk had been sent to assist and had just arrived on scene when they went down.
It appears all 4 of the chopper crew survived. 3 who were on board during the crash and the winchman (or whatever the Americans call them) who was still on the deck of the freighter with the ships master. Those lost were from the ships crew. The "crewman" interviewed said the engine noise suddenly decreased and he just had time to think "uh oh" and then they hit the water.