Roughly 200 first responders took part in the second annual 9/11 Memorial Tower Climb on Saturday in Fort Worth to honor the first responders who died on 9/11.

Participants climbed 36 flights of stairs three times to approximate the 110 stories ascended by first responders at the New York World Trade Center in 2001, according to Fort Worth Magazine.

A registration fee of $40 was collected from each participant and donated to the National Fallen Firefighters Foundation and the Brotherhood of the Fallen.

A moment of silence was observed at 8:46 a.m. to commemorate the moment American Airlines Flight 11 hit the North Tower. Afterward, a pipe and drum rendition of “Amazing Grace” played as climbers began the trek, as reported by The Fort Worth Business Press.

Five other moments of silence were held during the event to represent significant moments during the attacks. The first two came at 9:03 and 9:37 a.m., representing the moments when the South Tower was hit by United Airlines Flight 175 and when the Pentagon was hit by American Airlines Flight 77, according to The Fort Worth Business Press.

The next two were held at 9:59 and 10:03 a.m. to commemorate the collapse of the South Tower and the crash of United Airlines Flight 93 in Shanksville, Pennsylvania.

Finally, a moment of silence was held at 10:28 a.m. to memorialize the collapse of the North Tower, per The Fort Worth Business Press.

On September 11, 2001, 2,753 people died in New York during the attacks on the Twin Towers, including 343 firefighters and paramedics, according to New York Magazine. Another 184 persons were killed in the attack on the Pentagon in Washington D.C. that same day, and 40 died in the crash of Flight 93 in Pennsylvania.

In the years since the terrorist attacks, the number of first responders who have died due to ailments related to the collapse of the Twin Towers has continued to increase.

“In the years that have followed, over 341 more FDNY members have died from rare cancers and diseases caused by the toxic dust at Ground Zero,” the Uniformed Firefighters Association of Greater New York posted on social media.

The New York Police Department said in a tribute on its webpage that many of the officers involved in search and recovery work have since died from 9/11-related illnesses. The department listed the names of 323 officers who have died, stating, “These officers were exposed to toxic and hazardous conditions during those efforts, and subsequently developed fatal illnesses.”

At this year’s Memorial Tower Climb, similar to last year’s event, those participating climbed in full gear and wore a lanyard with the name and photo of a first responder on duty during the attacks, as reported by Fox 4 KDFW.

President and CEO of City Center Management, Johnny Campbell, said the “climb is a solemn and significant occasion. … [W]e believe it’s important to continue to honor the dedication to duty and ultimate sacrifice these brave men and women witnessed at the World Trade Center, but also to rally around our local first responders and show our support for the sacrifice they continue to make for us every day.”

“In addition to our local police and fire department personnel, we are thrilled to have so many men and women representing departments from all across North Texas, such as Lake Worth, Lancaster, Grand Prairie, North Richland Hills, Cresson, and others,” added Campbell, according to The Fort Worth Business Press.

Elizabeth Beck, a Fort Worth District 9 City Council member, was a United States Army Reserve member at the time of the attacks. She said, “That moment was something that changed our nation.”

“I remember when this happened, and knowing once that plane hit the Pentagon, knowing what was next for me,” said Beck, according to The Fort Worth Report. “It definitely changed the trajectory of my life and so many other folks that I served with.”