The builder of a rocket that had to be destroyed after it careened out of control over the Atlantic Ocean focused its investigation Friday on engine failure.

A multimillion-dollar Japanese broadcasting satellite was aboard the doomed rocket. The television network in Tokyo that was counting on quick use of the spacecraft said the loss may result in service disruption for its 4 million customers.The Atlas-Centaur rocket was blown up by remote control six minutes after it lifted off Thursday night from Cape Canaveral Air Force Station, sending a hail of debris into the ocean about 240 miles away.

The explosion was too far away to be seen or heard from shore. But several pilots of airliners flying 500 miles away reported seeing the wreckage fall.

The rocket and satellite were valued at more than $100 million. The spacecraft was insured.

Rocket builder General Dynamics Corp. said the problem occurred right after the Centaur upper stage separated from the Atlas booster as planned.

A preliminary review indicated that one of the two engines on the upper stage failed to ignite, the company said. The 30-foot Centaur, with the satellite still attached, immediately lost speed and began tumbling toward Earth.

The Air Force sent self-destruct commands to keep the rocket from falling on land. It was destroyed at an altitude of 109 miles.