Two small planes collided Saturday morning in New Jersey (search), killing at least five people and sending one aircraft plunging into the back yard of a home.

One person was trapped in a Cessna 150 (search), but alive, and rescue workers were trying to free that person, said Holly Baker, a spokeswoman with the Federal Aviation Administration (search).

The Cessna collided with a Piper PA-28 (search) near Kinnelon (search), and the Piper broke into pieces, Baker said. Baker said neither plane had filed flight plans so it was not clear how many people were involved in the crash.

She said nobody on the ground was injured.

One plane crashed about 9:15 a.m. in the wooded back yard of a home across the street from John Yago's house in Kinnelon. It was unclear whether it was the Cessna or Piper.

"I walked over and all you could see when you look behind the house was the tail sticking straight up out of the ground," Yago said.

Yago said his wife thought she heard a noise in their home's kitchen, but he didn't hear anything as he worked on his computer. When he saw police cars arrive on the street, he went outside to see what was going on.

Yago said the aircraft he saw was a two-passenger plane and that his neighbor's home was not damaged.