Air tankers were grounded Wednesday in California after one of the aircraft crashed into a steep canyon wall while fighting a blaze in Yosemite National Park, killing the pilot, officials said.

The agency normally does such a safety stand-down after a crash, State Department of Forestry and Fire Protection spokeswoman Alyssa Smith said.

It was not clear how long the planes would be out of service.

The agency has about 22 of the S-2T air tankers. Other aircraft were still available to assist with fires, officials said.

The pilot's family has requested no name be released until all immediate family members can be notified, Smith said. Rescue crews planned to recover the body on Wednesday. The pilot was believed to be the only person aboard.

Rescue crews hiking through extremely rugged terrain found the wreckage and confirmed the pilot's death several hours after the plane crashed on Tuesday, Smith said,

The plane went down within a mile of the park's west entrance, Yosemite spokesman Scott Gediman said.

California Highway Patrol Sgt. Chris Michael said he was stopping traffic along state Route 140 at the west entrance to the park when he saw the crash.

"I heard a large explosion, I looked up on the steep canyon wall and saw aircraft debris was actually raining down the side of the mountain after the impact," he told The Associated Press by telephone.

The fire was spreading up the canyon wall, and it appeared the pilot was trying to lay down fire retardant to stop its progress, Michael said.

Pieces of the aircraft landed on the highway and came close to hitting fire crews on the ground, but no one on the ground was injured, he said.

The airplane, manufactured in 2001 and based out of Hollister is flown by a single pilot and normally has no other crew members. The tanker uses twin turbine engines and is capable of carrying 1,200 gallons of retardant, said another CalFire spokesman, Daniel Berlant.

The pilot was an employee of DynCorp., a contractor that provides pilots for all CalFire planes and maintenance for the department's aircraft, said Janet Upton, a CalFire spokeswoman.

The fire began Tuesday near Route 140, which leads into the heart of the park and remained closed on Wednesday. It had grown to about 210 acres and there was no containment.

The fire was burning away from the park toward Foresta, where 60 homes were evacuated. The community was not in any imminent danger and was benefiting from containment lines created during a previous fire, Yosemite National Park spokeswoman Kari Cobb said.

The National Transportation Safety Board and Federal Aviation Administration were investigating the crash of the tanker.

FAA records show the plane is registered to the U.S. Forest Service, which originally provided the plane to CalFire, Upton said.

The last time a CalFire air tanker crashed was in 2001, when two tankers collided while fighting a fire in Mendocino County, killing both pilots, Berlant said.

The agency had another plane crash in 2006, when a fire battalion chief and a pilot were killed while observing a fire in a two-seat plane in Tulare County.