President Donald Trump posthumously awarded the Presidential Medal of Freedom on Tuesday to Welles Crowther, the 24-year-old volunteer firefighter whose final acts of courage inside the World Trade Center saved as many as 18 people.

Trump presented the nation’s highest civilian honor during the Tunnel to Towers Foundation’s “Steel Across America” event near the White House, part of a nationwide commemoration marking 25 years since the Sept. 11 terrorist attacks.

“Today we also remember another hero of 9/11,” Trump said before recounting how Crowther repeatedly entered the smoke and wreckage of the South Tower to guide strangers toward safety.

Crowther became known simply as the “Man in the Red Bandana,” but the survivors he helped did not initially know his name. They remembered only the calm young man who appeared amid the chaos with a red bandana covering his nose and mouth.

A Rescuer Appears In The Smoke

Crowther was working as an equities trader for Sandler O’Neill & Partners on the 104th floor of the South Tower when the attacks began.

A graduate of Boston College and a volunteer firefighter since the age of 16, he drew upon his emergency training as smoke, fire and confusion engulfed the building.

According to the National September 11 Memorial & Museum, Crowther reached the devastated 78th-floor sky lobby and discovered injured survivors near the only viable stairwell. He carried one badly wounded woman on his back, led a group downstairs and then climbed back toward the danger to help others.

“He just did things that people said were not even imaginable,” Trump said Tuesday. “He willingly made all of these trips up and down, up and down, over and over again, saving life after life.”

Crowther reportedly helped extinguish fires, administered first aid and issued clear instructions to survivors who were frightened, injured and struggling to see through the smoke.

He could have continued down the stairs and escaped. Instead, he turned around.

Again and again, Crowther went back for people who could not save themselves.

Investigators later found his remains in the wreckage of the South Tower alongside firefighters and other emergency workers. He was believed to have still been participating in rescue efforts when the building collapsed.

The Clue That Revealed His Identity

For months, Crowther’s family did not know what he had done after leaving a final voicemail telling his mother he was safe.

The answer emerged in 2002, when survivors publicly described the mysterious rescuer who had directed them through the burning tower. They could not provide his name, but they all remembered the red bandana around his face.

After reading their accounts, Crowther’s mother contacted the survivors and showed them photographs of her son. They recognized him as the man who had saved them.

“His family learned through witness accounts that Welles’ compassion, leadership and unwavering commitment to others were key to his courage in his final moments,” the Welles Remy Crowther Charitable Trust recounts.

The red bandana had been part of Crowther’s life since childhood. His firefighter father had given it to him when he was a boy, and Crowther continued carrying one as an adult.

Trump recalled that Crowther once made a striking prediction about the simple piece of red cloth: “With this red bandana, I’m going to change the world.”

“Little did he know, on September 11th Welles saved many, many people before losing his own life,” Trump said.

A Hero’s Light Still Shines

Trump first announced the award during a May appearance in Crowther’s home county in New York after Rep. Mike Lawler (R-N.Y.) advocated for the recognition.

“It’s such a beautiful thing that even 25 years later, Welles’ light still shines brightly,” Crowther’s mother, Alison, said at the time, according to Fox News.

One of Crowther’s bandanas now sits inside the 9/11 Memorial & Museum, where it serves as a reminder that even in one of America’s darkest hours, extraordinary courage could be found in an ordinary object—and in the young man wearing it.

His legacy also lives on through the charitable trust established in his name, educational programs teaching young people about character and service, and Boston College traditions honoring its fallen alumnus.

The “Steel Across America” tour has carried a massive beam recovered from the World Trade Center through communities across the country. Tunnel to Towers said the journey was created to preserve the memory of the 2,977 people killed on Sept. 11 and the bravery demonstrated that day.

“This tour is about ensuring that every generation can remember, and truly understand, what happened 25 years ago,” Tunnel to Towers Chairman and CEO Frank Siller said when the national tour was launched.

Standing near that battered piece of steel Tuesday, Trump formally placed Crowther among the nation’s most honored civilians.

“Today, in honor of his incredible bravery and all of the other countless unknown acts of heroism that day, it is my privilege to award” Crowther the Presidential Medal of Freedom, Trump said.

Nearly 25 years after Crowther made his final trip up the stairs, the identity of the Man in the Red Bandana is no longer a mystery.

His name—and what he chose to do when others needed him most—will not be forgotten.