JACKSONVILLE (CBSMiami) – The US Coast Guard plans to call off its search Thursday night for two missing firefighters who disappeared off Florida’s coast.

Jacksonville Fire and Rescue Department firefighter Brian McCluney and Justin Walker of the Fairfax County Fire and Rescue Department in Virginia left on a fishing trip last Friday out of Port Canaveral.

They were supposed to return that night. They didn’t and a search was launched.

During the search, boaters recovered a tackle bag belonging to one of the firefighters. But now it appears time has taken its toll.

“We have reached a point where our computer modeling and our ability to search a given location are no longer allowing us to search with any reasonable degree of a probability of success,” said Capt. Mark Vlaun, a Coast Guard sector commander.

Search by planes and boats from the central Florida coast to the coast of South Carolina had covered 105,000 square miles.

Vlaun said the search and rescue operations could restart if other clues resurface.

Interim Jacksonville Fire Chief Keith Powers said family members were heartbroken by the news.

“That is an extremely tough decision because we have a brother out there we just haven’t been able to find,” Powers said.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)