From the ashes of Flight 93 came the story of Todd Beamer. Just before passengers started fighting back, he was on the phone with operator Lisa Jefferson.
According to Jefferson, "He said, 'Okay, let's roll.'"
But, as CBS News Correspondent John Blackstone reports, has America's embrace gone too far?
Paul Pancucci runs one of dozens of Internet businesses selling "Let's Roll" T-shirts.
Pancucci says, "We wanted the letters to be bold and to make a statement."
The U.S. Patent office has received at least 19 applications to use "Let's Roll" as part of a trademark.
One of those claiming the phrase is the Todd Beamer Foundation that sells its own line of clothing and baseball caps to raise money for charity. Beamer's widow, Lisa, has just written a book titled "Let's Roll," a phrase that's been an inspiration to many.
"There's also a piece of America that's just a marketing machine, too, and wanting to profit off of things like this," Beamer told CNN's Larry King.
When Florida State adopted "Let's Roll" as the motto of its football team, Coach Bobby Bowden found himself defending the choice.
Bowden explained, "Let's roll, let's go get it, you know, and so I thought it'd be a good tribute to those who died."
The Beamer Foundation agreed it is a tribute, and is now getting a share of the profits from "Let's Roll" gear sold in Florida State colors.
Still some on campus remain uneasy with the motto.
"It's not necessarily something that should be put on a T-shirt and shouted out," says one student.
"Let's Roll" has inspired songwriters, including Neil Young.
But its political usage led Larry Lenza to produce a protest T-shirt.
Lenza, of PoliticalClothing.com, says, "It was very unfortunate because people had gathered around the words first and then it was used in a cynical, political way."
Anthony Pratkanis, a professor at U.C. Santa Cruz says, "In my mind it's a phrase that's gone to the ages. It's become part of what it means to be American."
Pratkanis, an expert in consumer psychology, says "Let's Roll" is open to abuse. "It plays on our emotions and gets us aroused and is used unfairly as a way of persuasion."
Two words are now balanced somewhere between the trivial and the sacred.