LOS ANGELES, July 26 (Xinhua) -- A small plane Wednesday crashed into a highway in the U.S. state of Utah, killing four people on board, local TV news said.

The accident occurred at about 1:00 p.m. (2100 GMT), when the plane Beech A36 Bonanza crashed half a mile away after taking off from an airport 60 km north of Utah's capital Salt Lake City.

Pictures posted on Twitter showed that the plane missed passing cars on the freeway, and nearby drivers pulled over immediately and rushed to help.

"The plane came swooping in and nose-dived into the middle of the freeway. It exploded with flames engulfing the entire street," one driver, April Demetropolis, told local KSL news channel. The crash was so close to her that she felt the vibration of the impact and heat from the explosion.

"It was a big black solid red ball of fire. There's no way you could have survived it," another witness, Randy Paulson, told KUTV news channel.

The list of victims has not been released and the cause of the accident is still under investigation.

Last month, a small plane crashed on a busy highway near Los Angeles, killing two people on board, including an experienced pilot who had just finished an 82-day journey around the world.