Four U.S. Fish and Wildlife Service biology field workers were evacuated from isolated Johnston Atoll Monday prior to the arrival of Hurricane Walaka.

A Coast Guard HC-130 Hercules aircrew from Air Station Barbers Point rescued the four workers as tropical storm conditions were expected to arrive this morning and intensify into hurricane-force conditions by the afternoon.

Hurricane Walaka is a Category 4 storm with sustained winds of 150 mph.

“Johnston Atoll is extremely remote and difficult to reach. Our resources place us in a position to lend assistance to our partners with the U.S. Fish and Wildlife Service and we are glad help,” Capt. Robert Hendrickson, chief of response for the Coast Guard’s 14th District, said in a news release. “We encourage anyone operating in the Pacific to keep an eye on the weather as this storm moves toward the Northwest Hawaiian Islands.”

The Fish and Wildlife Service requested the evacuation at 12:30 p.m. Monday. The atoll is home to a four-member field biology crew working out of a year-round field camp at the Johnston Atoll National Wildlife Refuge.

“The safety of our staff and volunteers is always our primary concern,” said Laura Beauregard, acting Refuge and Monument Supervisor for the U.S. Fish and Wildlife Service.