September 11: 8:21 a.m. Flight 77, a Boeing 757, departed Dulles for Los Angeles.

September 11: 9:37 a.m. About an hour after takeoff from Dulles International Airport, American Airlines Flight 77 slammed into the Pentagon at more than 500 mph, carving a hole five stories high and 200 feet wide. While in the Pentagon that day, 125 individuals died; 59 died aboard American Airlines Flight 77. American Airlines issues statement confirming that it lost two aircraft the morning of September 11, 2001.

September 12: To honor the 184 victims who died during the tragic event, a makeshift memorial was created on the Arlington Memorial Cemetery fence.

June 11: Exterior reconstruction is completed on the Pentagon. At a small ceremony marking the progress, officials announce the design competition for the Pentagon Memorial.

March 3: Keith Kaseman and Julie Beckman, two young New York architects, were chosen to design the Pentagon Memorial. More than 1,000 entries were submitted.

March 3, 2005: In Pevely, Mo., the first stainless-steel prototype that will be used for the 184 benches was made. The first prototype was trimmed, polished and tested for flaws. "Now we can come back and tell all the family members that this is going to happen," said Jim Laychak, who lost a brother at the Pentagon on Sept. 11, 2001. "I knew we were going to get it built, but this makes it tangible and real. Now you can see it and touch it and you can imagine what 184 of them together is going to look like."

May 9: Tom Heidenberger and five other riders arrive at the Pentagon, after a 33-day cross-county bike ride, the "Airline Ride Across America." The bike ride, crafted by Heidenberger to raise money for the September 11 memorial funds, began in Los Angeles on April 2. Heidenberger's wife, Michele, died aboard Flight 77.

June 15 Groundbreaking ceremony for the memorial. Officials unveil a marker for the Pentagon memorial to Sept. 11.

June: Bench production begins in Pevely, Mo. Three to four 1100-pound stainless steel castings will be produced each week.

August: First 14-foot bench arrives in Elk Grove Village, Ill. at the Bucthel Metal Finishing Corp., where it will be polished into a flawless memorial bench.

April: Final benches are forged at MetalTek International, a foundry 30 miles south of St. Louis.

July: The benches for the youngest victims, Dana and Zoe Falkenberg, sisters from University Park, arrive at the park.

September: Dedication of the Pentagon Memorial. The site will be open 24 hours, 7 days a week.