Flight 93 took off from Newark International Airport in New Jersey but never reached its target.

As the Twin Towers of the World Trade Center burned and a plane hit the Pentagon at full speed around 9:30 a.m., a fourth and final plane--United Airlines Flight 93--was hijacked over Ohio. Four terrorists overpowered the crew and redirected the plane toward Washington, D.C.

Unlike the other hijackings, the Flight 93 mission didn't go smoothly for the terrorists. The terrorists had to fight off the pilots and some crew members with knives before the plane came under their control. The terrorist pilot then lied to the passengers, claiming that a bomb was on board and the terrorists simply wanted to land the plane and make demands.

But the passengers soon realized that the terrorists had planned a suicide mission. The passengers took a vote and decided to storm the cockpit. At 9:57 a.m., passengers began hammering at the cockpit door, using a food cart as a battering ram. To throw them off, the terrorists made sharp turns and steep dives and climbs with the plane, but the passengers persisted.

President George W. Bush visited the site of the Flight 93 crash on the first anniversary of 9/11. The site remains a memorial to the victims.

Realizing that they couldn't hold off the passengers for long, the terrorists pointed the plane down and crashed it into an empty Pennsylvania field. All 44 people on the plane were killed. If the passengers hadn't revolted, the plane likely would have struck either the White House or the Capitol Building.

While Flight 93 was still in the air, American leaders ordered a stop to all flights in the United States, and travel ceased in some other countries, too. But the attacks were already over. In total, 2,996 people died on 9/11, and many more died from injuries and health complications later.

Use this activity to review the events of 9/11.