ST. LOUIS — Seventeen years ago, 2,977 people lost their lives in the horrific events of September 11 in New York City, Washington D.C., and Shanksville, Pennsylvania. In the years since the country's worst terrorist attack, events around the nation have gathered to honor those who lost their lives on that fateful day. In St. Louis, there are a number of free events open to the public throughout Tuesday.

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1. March to the Arch

Beginning at 9:11 a.m., the March to the Arch is a 21-mile memorial walk which will begin in west St. Louis County and conclude at the base of the Gateway Arch. The starting point for the march will be at Mike Duffy's Pub & Grill at 141 and Clayton Road in Kirkwood. The walk is free to participate in, but those interested in attending are encouraged to bring their American flags.

2. 9/11 memorial stair climb at Monks Mound

The seventh annual Brevity Fitness 9/11 Memorial Stair Climb at the Cahokia Mounds will kick off 5 p.m. and will feature several laps variations to choose from — five, six and nine laps. Five laps equate to the number of flights climbed by first responders in the North Tower of the World Trade Center, six laps equate to flights climbed in the South Tower, and nine laps equate the full 110 flights of stairs. Those interested in climbing should wear a weighted vest or backpack.

3. Patriot Day reveille, ceremony at Scott Air Force Base

The Scott Air Force Base will be holding a 30-minute memorial ceremony in front of the 375th Air Mobility Wing Headquarters, building P-3, beginning at 7 a.m. The outdoor event is free to attend, but the base recommends planning ahead to arrive at the Shiloh Hate Visitors Control Center by 6:40 a.m. for an escort to the ceremony. Carpooling is recommended.

4. Two-mile Memorial Run at Scott Air Force Base

Following the conclusion of the ceremony outside the 375th Air Mobility Wing Headquarters, the base will hold a two-mile Memorial Run at 7:45 a.m. The run will kick off at the Parade Grounds and is free to all participants. For more information, call the Scott Air Force Base Fitness and Sports Center at (618) 256-1218.

5. Army JROTC cadets commemorate 9/11 victims

Cadets with Vashon High School's Army JROTC program will pay remembrance to the 2,977 victims who lost their lives during a ceremony at the John Cochran VA Medical Center in St. Louis. The event is set to begin at 10:15 a.m. and last around 45 minutes, and will include a Presentation of Colors and wreath posting, as well as first responders and U.S. military vehicles on display.

6. Florissant VFW Post pays tribute to 9/11 victims

The north St. Louis County VFW Post, located at 410 St. Francois Street, will host a remembrance ceremony in Old Town Florissant for the lives lost at both the World Trade Center and the Pentagon beginning at 7 p.m. Several speakers will be present, including Florissant Mayor Thomas P. Schneider, Chief Tim Lowery, Fire Chief Scott Seppelt and Deputy Director Brendan Fahey from Sen. McCaskill's office.

7. Belleville's Moment of Remembrance Ceremony

The ceremony will honor the nearly 3,000 innocent victims of the terrorist attack beginning at 11:30 a.m. at Belleville's September 11 Memorial Walkway of Southern Illinois, located at 1125 Illinois Street. The walkway features a 35.25 foot-long steel column from the collapsed World Trade Center.

8. O'Fallon, Mo., honoring Patriot Day at First Responders Memorial

Beginning at 8:30 a.m., the event dedicated to first responders, police, firefighters, and paramedics who stepped forward to rescue the victims of 9/11 will be held at the First Responders Memorial. The ceremony, located at 100 North Main Street, will include remarks by Mayor Bill Hennessy, Police Chief Roy Joachimstaler and other special guests. Those who attend will be able to place flowers at the memorial.