NEW YORK — They gathered at a hole in the ground in Lower Manhattan, a lonely patch of earth in rural Pennsylvania and a spot near the healed breach in the seat of U.S. military power, the Pentagon.

The crowds were smaller than in past years, but hundreds again attended the sites of the worst terrorist attack in U.S. history to remember and mourn those lost three years ago Saturday, on Sept. 11, 2001.

A few minutes before 8:46 a.m., the same moment the first plane hit the north tower, the families of those who died at the World Trade Center began the rituals of grief.

There was the stoic descent seven stories into the earth, perhaps for the last time as construction proceeds rapidly on the site, flowers and mementoes in hand; then the four aching moments of silence to mark the impact of each plane and the collapse of each tower, and finally the recitation of 2,749 names by those left behind, the melancholy tolling of church bells, and the lonely, mournful echo of taps.

Standing on a balcony overlooking ground zero, Gov. George E. Pataki said: "We are not going to forget. Sept. 11 is never going to become just another day."

This year mothers and fathers recited the names of their dead daughters and sons; grandparents named grandchildren.

Voices quaking, parents and grandparents in pairs came to the lectern to read the names of the dead. The roll started with Gordon M. Aamoth Jr. and ended with Igor Zukelman.

In keeping with past years, there were no speeches. Pataki quoted President Dwight D. Eisenhower — "There's no tragedy in life like the death of a child" — and read a poem from a scrapbook kept in a private room in a nearby office building, high above the trade center site, where family members often gather.

Former Mayor Rudolph W. Giuliani read President Abraham Lincoln's letter to a widow who lost five sons in the Civil War; it ends with Lincoln telling her of "solemn pride that must be yours to have laid so costly a sacrifice upon the altar of freedom."

Shortly after 8 a.m., families of those who died began filing into Arlington National Cemetery in Virginia for a ceremony to commemorate the attack on the Pentagon.

On the rural field in western Pennsylvania, where one of the hijacked airliners crashed, more than 1,000 people gathered to remember those who died there.

At hometown memorials across the New York region, friends and relatives of the dead gathered to remember them. A half-dozen towns in New Jersey planned to unveil new monuments to the victims of the attack. In Chappaqua, N.Y., residents dedicated a Flag of Remembrance for the victims, and in Danbury, Conn., a new memorial was unveiled at a city park.