In the United States, a small plane crashed on a Utah highway, killing two couples heading for a vacation but narrowly missing cars when it barreled across the lanes through a gap in traffic.<br/><br/>Federal Aviation Administration spokesman Allen Kenitzer said the plane went down shortly after takeoff from a municipal airport yesterday popular with private pilots north of Salt Lake City.<br/><br/>No injuries were reported on the ground after it snarled traffic and left behind blackened wreckage.<br/><br/>The FAA and the National Transportation Safety Administration are investigating the cause of the crash. It closed most lanes of Interstate 15 in Riverdale, about 35 miles north of Salt Lake City.