ENGLEWOOD, Colo. --Head Coach John Fox didn't wear his typical white Broncos hat for Wednesday practice.

Instead he sported a blue hat with the letters NYPD displayed across the front as well as the back.

The hat represented his tribute to all of the first responders in New York City on the 12th anniversary of the Sept. 11, 2001 attacks.

"There were a lot of first responders that lost their lives, whether it was the port authority or FBI agents or the fire department," Fox said. "A lot of brave people lost their lives that day."

Fox has an especially close connection to the tragic events of that day as he was in his fifth season as the New York Giants' defensive coordinator in 2001.

He had just returned to the New York area from Denver after the Broncos defeated the Giants 31-20 on Monday Night Football to open the NFL season on Monday, Sept. 10, 2011.

"It's probably one of my more vivid adult memories so far in my 58 years on the Earth," Fox said. "It's something I'll never forget."