SALMON, Idaho (AP) -- Officials are investigating why 20 firefighters had to abandon gear and flee rising flames while working the Cabin Creek fire, which was fully contained Wednesday.

The fire burned 783 acres in the Salmon Challis National Forest about 8 miles west of North Fork. Two helicopters and 285 firefighters battled the blaze, at an estimated cost of $912,000, National Interagency Fire Center officials said.

Firefighters were aided by rainy weather over the past few days, officials said, including three-quarters of an inch on Monday.

But Friday, the fire was behaving erratically and a 20-person crew that was digging a fire line on a steep slope was forced to make a dash to a previously identified safety zone uphill. Some firefighters shed gear as they ran up the mountain.

An after-action review team, including fire experts from the Ashley National Forest in Utah and the Beaverhead-Deerlodge National Forest in Montana, has been called in to investigate the incident.

Acting Forest Supervisor Renee Snyder said the review was not a reaction to increased scrutiny following last year's deaths of two firefighters on the Cramer fire. Salmon-Challis National Forest officials have been blasted in three separate investigations for failing to follow basic safety rules during that blaze.

The crew fighting the Cabin Creek fire had a variety of experience levels, she said, and for some members, it was their first real fire.

"Because of the reaction of the crew -- some folks were upset -- we wanted an objective review of what happened," Snyder said.

Fred Batley, a Forest Service dispatcher, said crew members told him that eight sets of fire line gear and a chain saw were burned after being discarded.

Snyder said that would be consistent with good firefighting rules.

"In tough country, that's what your training teaches you. You drop packs and lose some weight so you can make better time," she said.

The review team is expected to make preliminary recommendations to forest managers on Thursday.

Snyder said initial reports indicate fire line supervisors did their job.

"We had some very highly experienced folks who were able to help keep the crew together and get them moving to the safety zone. Everybody came out safely at the end," she said.

AP-WS-07-21-04 1112EDT