US Senator Paul Wellstone was killed in a plane crash in Minnesota today, his office said the death throws into question the Democratic Party's one seat majority in the US Senate.
"The senator was on the plane as was his wife and one of their children," said Mr Wellstone's campaign manager Mr Jeffrey Blodget.
Aviation officials said eight people were on the twin-engined plane which crashed near Eveleth in northern Minnesota this morning.
A Federal Aviation Administration spokesman told reporters that contact was lost with the plane about two miles (three kilometers) from Eveleth airport. The plane was on a flight from Minneapolis.
Mr Wellstone had chartered the Beechcraft King Air 200 plane for his campaign for re-election for Congress. The vote is to be held on on November 5th.
"The senator logs hundreds of thousands of miles in small planes. He was with his trusted pilots. The unthinkable happened," said Mr Blodgett.
The US Senate is currently controlled by the Democrats by one vote. Normally, Minnesota Governor Jesse Ventura, an independent, will have to appoint a replacement.
Mr Wellstone was one of the most liberal and unconventional members of the Senate.