Anchorage is Alaska's largest city.

The U.S. Coast Guard in Alaska says a fire Thursday at an offshore natural gas platform in Alaska's Cook Inlet forced four people to evacuate, but the environmental risk is considered minimal.

The Coast Guard says the fire appeared to be out by 11 a.m., but vessels at the scene were still battling smoke. The platform 8 miles offshore is among 12 platforms in the inlet that are operated by Hilcorp Alaska LLC.

No spill has been reported.

Hilcorp spokeswoman Lori Nelson says the fire broke out at about 7:30 a.m. and was limited to the crew living quarters, which appear to be a total loss. The fire is not believed to be production-related.

Nelson says the crew was safely evacuated by a Hilcorp helicopter crew.

Responders say the cause of the fire at the Baker platform is unknown.