Relatives of passengers and crew members who perished on United Airlines Flight 93 will hold a private funeral and reinterment service for unidentified remains at the crash site the day after the 10th anniversary of the Sept. 11 attacks.

The Sept. 12 ceremony will take place at what's called the Sacred Ground site in the fields near Shanksville, the rural area southeast of Pittsburgh where the 40 passengers and crew members lost their lives after fighting terrorists for control of the plane.

The Sacred Ground is located within the Flight 93 National Memorial but is closed to the public. On Sept. 12, the entire memorial will be closed to the public until 2 p.m. to allow for the private service.

The service will be led by Somerset County coroner Wallace Miller. The remains have been kept in three caskets inside a crypt in the coroner's care for the past 10 years.

At the service, the caskets will be placed in the earth at the crash site. Attendees will include family members, National Park Service officials and invited guests. To honor the privacy of the families, the ceremony will be closed to the public and the media.

Carole O'Hare, whose mother, Hilda Marcin, was a passenger on Flight 93, said the crash victims were heroes.

"They were also our loved ones," O'Hare said Thursday. "This ceremony provides an opportunity for us to reflect quietly on their extraordinary lives."