FBI investigators have concluded that no explosive was involved in the crash of United Airlines Flight 93, the only one of four aircraft hijacked Sept. 11 which did not claim a life on the ground.

Passengers on the flight, in cell phone calls made before the crash, said one of their captors had what appeared to be a bomb strapped to him. At least three of the passengers said they planned to confront the hijackers just before the plane crashed in Somerset County, Pa., killing all 44 on board.

At a news conference, FBI agent Bill Crowley said that the field near Shanksville, Somerset County, has been turned over to the county coroner and that 95 percent of the plane found at the site has been turned over to United Airlines.

Crowley said the FBI has determined from the on-site investigation that no explosive was involved in the crash.

He said that no bomb residue was found at the crash site and that there was no evidence that the plane broke up before it hit the ground.

"Nothing was found that was inconsistent with the plane going into the ground intact," Crowley said.

Crowley also gave no details about any information taken from the cockpit voice recorder or the flight data recorder, which were found at the site.

He said that Somerset County Coroner Wallace Miller will take over responsibility for the crash site, which will be enclosed with a fence and patrolled. Eventually, the hole where the plane crashed will be filled in and replanted.

After the crash about 10 a.m. Sept. 11, FBI officials said they expected the work at the site to take three to five weeks. On Monday, Crowley said good weather and a large number of workers -- as many as 1,500 in less than two weeks' time -- allowed the work to go more quickly.

He said that the biggest piece of the aircraft which was found was a piece of the outer portion of the fuselage, which measures about 6 feet by 7 feet and included four windows. The heaviest piece found was a part of an engine fan weighing about 1,000 pounds, Crowley said.

Coroner Identifies More From Flight 93

Meanwhile, seven more victims of Flight 93 that crashed in Pennsylvania were identified using fingerprints and dental records, a coroner said Sunday, bringing the total of those confirmed dead to 11.

Miller declined to name the identified victims or release information about them.

"My priority is protecting the privacy of the families," Miller said.

The remaining 33 victims will likely require DNA testing, which could take months, Miller said.

All 44 people aboard were killed Sept. 11 when the plane crashed into a field about 80 miles southeast of Pittsburgh, shortly after two planes crashed into the World Trade Center and one into the Pentagon.

The Boeing 757 was the only one of the four crashed planes that didn't take any lives on the ground.

Several passengers on Flight 93 made cell phone calls to people on the ground saying they planned to attack their hijackers. The flight from Newark, N.J., to San Francisco was heading west when it made an abrupt turn near Cleveland and veered back across Pennsylvania before crashing near Shanksville, Somerset County.

Officials have speculated that the jetliner was headed toward a target in Washington when it crashed.

For the past two weeks, investigators had been working at the site to collect evidence and human remains. They have recovered the plane's flight data recorder and the cockpit voice recorder from the site.

Pittsburgh Economy Suffering

Pittsburgh's economy has suffered since the Sept. 11 attacks.

According to the Convention and Visitors Bureau, 22 conventions have been canceled, postponed, or altered.

Downtown hotels report losses from the reduced flights and passenger loads at Pittsburgh International Airport.

The Westin Convention Center is running at about 60 percent of its normal occupancy.

Giant Flag Centerpiece For Memorial Service

A seven-ton flag will be the centerpiece of a memorial service Monday in Somerset County.

Volunteers unfolded a 210-by-411-foot flag Sunday near the Jennerstown Speedway. Spectators said they were shocked at the size of the flag.

Ted Dorfman, of Greensburg, owns the flag, which is believed to be one of the biggest in the world.

There will be a memorial service for the victims of Flight 93 Monday at 6:30 p.m. in a field near the Jennerstown Speedway. It will be a free service with music and poetry.

Previous Local Stories:

Sept. 23, 2001

Pittsburgh Rallies For Peace

Sept. 22, 2001

Report: Struggle Occurred On Flight 93

Sept. 21, 2001

How To Take Action, Help Others

Sept. 20, 2001

Pilot Witnesses Flight 93's Final Moments

Sept. 18, 2001:

Local Company Wants To Give New York Statue

Local WTC Survivor Describes Her Escape

Sept. 17, 2001:

Relatives, Friends Tour Somerset County Crash Site

Play Ball! Pittsburghers Love New York

Sept. 16, 2001:

'Let's Roll,' Flight 93 Victim Heard To Say Before Crash

Sept. 15, 2001:

FBI Explains Other Planes At Crash, Local Rescue Team Returns From NYC, Steelers Among Crowd At Vigil

Sept. 14, 2001:

Second Black Box Found At Somerset Site; Governor Leads Vigil

Sept. 13, 2001:

Flight 93 Data Recorder Found

Sept. 12, 2001:

Alleged Partial Flight 93 Cockpit Transcript Obtained

FBI Searches New Castle Apartment

Pittsburgh International Airport Revamping Security

FBI Interested In Local Townhouse, Car

Westmoreland County Man Among Crash Victims

Munhall Woman's Brother Calls From WTC Rubble

Sept. 11, 2001:

Plane Crashes In Somerset County

Flight 93 Passenger Said He Planned Action

Cities Knew Plane Was Coming, But Not Where

Tearful Ridge Promises Help From Pa.

State Watches, Reacts As Attacks Unfold