Sen. John Heinz, R-Pa., was killed Thursday when a small airplane and a helicopter collided and crashed in a school yard shortly after noon, his office said.

Unconfirmed reports said several others were also killed.A man working down the street said he saw two bodies.

"I ran up the street and I saw a little boy on the ground, his clothes

burned off, and another one up on the hill, that one was an adult," said Mike Notaro. "They were both covered."

Police immediately roped off the area as parents rushed to the school to check on their children. Police pleaded with parents to stay home.

Students were inside the Lower Merion school building at the time. Officials said some may have suffered minor injuries.

The FAA at the Philadelphia International Airport said tower personnel identified one of the aircraft as a twin-engine Aerostar PA-60. They were unsure of the helicopter.

The aircraft burst into flame on impact and went down in a ball of flame and thick, black smoke, fire officials said.

Authorities said the pilot of the airplane said he had three people aboard and reported trouble with the landing gear. Police sent the helicopter to investigate.

Officials said they did not know how many people were aboard the helicopter.

In Washington, a spokesman for the National Transportation Safety Board said a team of investigators was being dispatched to Philadelphia in an attempt to learn the cause of the accident.

Heinz, heir to the H.J. Heinz food fortune, was one of the richest members of the Senate.

A 52-year-old Pittsburgh native, Heinz was first elected to the Senate in 1976 and would have been up for re-election to a fourth term in 1994.

He was the second ranking Republican on the Senate Banking, Housing and Urban Affairs Committee and also was the ranking GOP member of Banking's securities subcommittee.