(AP) Volunteers crawled or walked side by side through a western Pennsylvania field in what could be the last search for debris and human remains from the crash of hijacked United Flight 93.

The roughly 125 volunteers skirted the scarred, barren hilltop where the Boeing 757 crashed on Sept. 11, instead concentrating on a patch of woods to search for airplane parts, personal effects and body parts that may have been shaken loose from the trees by wind, snow or rain over the past eight months.

"That was the area we hadn't really completely canvassed in the fall. The first time the weather kind of closed in on us," said Somerset County Coroner Wallace Miller.

After the 3-hour search on Saturday, workers had filled scores of buckets with metal, insulation and wire, and filled a 5-gallon bucket with remains.

Miller said it wasn't known yet if all the remains were human.

Flight 93 was the only one of four planes hijacked on Sept. 11 that didn't kill anyone on the ground. The plane was believed to have been headed for a target in the Washington when some passengers made phone calls indicating they were going to fight off the terrorists. All 44 people on board were killed.

Using fingerprints, dental records and DNA, Miller has identified remains from the 40 passengers and crew and the four terrorists. Identified remains and personal effects have been given to the victims' families, while remains believed to be terrorists' because they didn't match samples from other passengers have been turned over to the FBI.

Miller said it was unlikely he would call for another search of the field, some 80 miles southeast of Pittsburgh.

U.S. Rep. John Murtha has asked Congress to authorize a permanent memorial at the site to be overseen by the National Park Service.