MEXICO CITY (AP) _ Four military planes flying in tight formation crashed Saturday during Mexican Independence Day festivities, killing six crew members, the Defense Department said.

One crew member parachuted to safety and remained hospitalized later Saturday.

A statement from the Defense Department said the accident occurred when an F-5 airplane collided with the rear of a T-33, and the falling planes forced two more T-33s to crash.

The planes collided as they flew through a canyon in western Mexico City, out of the sight of residents watching 121 military planes perform to celebrate the 185th anniversary of Mexican independence.

Witnesses heard a huge explosion and saw a column of black smoke rise from the crash site. Television footage showed pieces of the airplanes strewn about a field.

Spectators said the planes did not seem well-coordinated during flights through downtown. Some reported seeing the planes deviate from their flight pattern.

Killed in the crash were Gen. Gonzalo Curiel Garcia, Maj. Jose Rivera Guttierez, Capt. Hector Ricardo Trejo Flores, and Lts. Mario Humberto Sanchez Garcia, Gerardo Vergara Mogollon and Gustavo Perez Estrada.

Lt. Gerardo Ceballos Peraza survived after parachuting to safety.

The planes were part of a celebration in which 26,000 soldiers marched through downtown Mexico City. Children dressed as famous Mexican revolutionaries rode on horseback, and hundreds of armored vehicles paraded down the broad Paseo de la Reforma.