Nineteen men changed the world on Sept. 11, 2001. In a matter of a few hours, the hate-filled men changed America - and the world - forever.

On the same morning 40 Americans began changing it back.

Armed with nothing more than small knives and a desire to give their lives to fulfill their deadly mission, 19 terrorists turned four passenger airliners into jet-fuel bombs four years ago today.

Of the four hijacked airliners, three hit their mark - two at the World Trade Center in New York and one at the Pentagon near the nation's capital. The fourth and final jet crashed in a field in rural Pennsylvania. On the afternoon of Sept. 11, 2001, that fourth plane was almost an asterisk to the smoldering piles of rubble left at the World Trade Center and the Pentagon.

However, it is that fourth flight, United Airlines Flight 93, which contained perhaps the most important story.

Before it crashed, the plane had changed course and appeared be headed toward Washington, D.C. It target was most likely either the U.S. Capitol or the White House.

From telephone calls received from aboard the jet, many people believe the passengers and remaining crew - who learned about the earlier crashes - decided not to sit back and accept their fate. They decided to "do something" as one of them told a loved one by telephone.

Passengers stormed the cockpit and although cockpit data recorders record the sounds of smashing plates and a struggle, most officials believe the passengers never actually made it into the cockpit, but their effort was just as successful.

Most likely scared the hijackers into crashing the plane since they knew the passengers would soon break through the cockpit door and retake the plane.

We'll never know for sure what occurred in the last few moments aboard Flight 93, but rest assured, the actions taken on board are among the most important, most courageous in American history.

The passengers aboard Flight 93 were the first heroes of the new war on terror. Each of the 40 heroes who gave their lives aboard Flight 93 started fighting back.

Today, as we mark the fourth anniversary of the terrorist attacks, let's remember the heroes of Flight 93 and remember the evil they defeated that day.

They "did something" in the face of great adversity. It's a lesson we should all take to heard, especially on this anniversary day.