Yet now, after all the wreckage has been cleared and the rebuilding has begun, their path is again blocked -- not by flying chunks of smoldering rubble, but by space constraints.
The first responders are not invited to this year's September 11 memorial ceremony at ground zero, New York City Mayor Michael Bloomberg's office confirmed Monday.
It's a painful insult for many of the approximately 3,000 men and women who risked their lives, limbs and lungs on that monumental day, puncturing another hole in a still searing wound.
In a statement, Bloomberg spokesman Andrew Brent said the commemoration ceremony is for the victims' families.
"While we are again focused on accommodating victims' family members, given the space constraints, we're working to find ways to recognize and honor first responders, and other groups, at different places and times," Brent said.
But first responder John Feal, founder of an advocacy group for the police officers, firefighters, civilian volunteers and others who worked at ground zero, assailed Brent's response, saying Bloomberg "lives in his own world."
"The best of the best that this country offered 10 years ago are being neglected and denied their rightful place," Feal said.