A look at events in New York City, Washington and Shanksville, Pa., marking the 12th anniversary of the Sept. 11 attacks:
NEW YORK CITY
The commemoration will take place at the National Sept. 11 Memorial & Museum plaza at the World Trade Center site. Families of victims in the 1993 and 2001 attacks will read the names of those who died, interspersed with moments of silence:
-- 8:46 a.m.: Moment of silence to mark Flight 11 hitting the north tower. Houses of worship have been asked to toll their bells.
-- 9:03 a.m.: Moment of silence to mark Flight 175 hitting the south tower.
-- 9:37 a.m.: Moment of silence to mark Flight 77 hitting the Pentagon.
-- 9:59 a.m.: Moment of silence to mark the fall of the south tower.
-- 10:03 a.m.: Moment of silence to mark the crashing of Flight 93 near Shanksville, Pa.
-- 10:28 a.m.: Moment of silence to mark the fall of the north tower.
-- 12:30 p.m.: Scheduled conclusion of ceremony.
Commemoration ceremonies with victims' families and survivors will be held at 9:30 a.m. at the Pentagon Sept. 11 Memorial in Arlington, Va.
-- 9:30 a.m.: Ceremony begins and will include a wreath laying.
-- 9:37 a.m.: Moment of silence marking Flight 77 hitting the Pentagon.
-- 1 p.m.: Pentagon employees for an event in the courtyard.
-- 10:03 a.m.: Bells will be rung and names of passengers and crew members will be read at the Flight 93 National Memorial.
9 a.m. - 10 a.m. PEACE OFFICERS MEMORIAL -- Staff and supporters of the National Law Enforcement Officers Memorial Fund, as well as dignitaries from law enforcement agencies, will gather at the National Law Enforcement Officers Memorial for a 9/11 remembrance ceremony. Location: National Law Enforcement Officers Memorial 400 Block of E Street, NW, Washington, DC
9:30 a.m. SEPT. 11 COMMEMORATION -- Arlington County will hold a ceremony to commemorate the 184 victims who lost their lives at the Pentagon on Sept. 11, 2001. Location: Courthouse Plaza, 2100 Clarendon Boulevard, Arlington, VA
10 a.m. 9/11 MEMORIAL -- Dover Air Force Base will host a dedication and unveiling ceremony of a 9/11 memorial. Location: Air Mobility Command Museum, 1301 Heritage Rd, Dover, DE.
10 a.m. SEPT. 11 REMEMBRANCE -- City of Alexandria hosts a Sept. 11 remembrance ceremony Location: Market Square, 301 King St., Alexandria, Va.
5 p.m. - 9 p.m. SEPT 11-BELVOIR -- Actor Gary Sinise and his Lt. Dan Band perform a free concert at Fort Belvoir as part of an "Invincible Spirit Festival" to mark the Sept. 11 anniversary. Location: Pullen Field, Fort Belvoir; 9500 Pohick Road; media enter through Tulley Gate