PORTLAND, Maine (AP) — An investigation into what caused a fishing boat carrying four Maine fishermen to sink off Cape Cod will likely take weeks or months, the Coast Guard said Friday.

The boat sank off Provincetown on Monday when it was en route to Gloucester, Massachusetts. Members of the Maine fishing community have been raising money for the families of the men lost at sea, who were Robert Blethen; Jeff Matthews; Michael Porper and Ethan Ward.

Coast Guard Petty Officer Amanda Wyrick said the cause of the sinking remained undetermined on Friday. The first Coast Guard crews to arrive on the scene discovered only debris and an empty life raft. The Coast Guard called off the search for the men on Tuesday.

The men were an experienced fishing crew that was bringing groundfish such as cod and haddock back into port, people familiar with the vessel have said. The vessel was called the Emmy Rose and it was based in Portland.

The investigation into the sinking could yield findings that can be used for updating policies and preventing future at-sea disasters, Wyrick said.

(© Copyright 2020 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)