Updated

Sen. Paul Wellstone, D-Minn., died in a plane crash Friday along with seven others, a Transportation Department official said.

"It does not look like there are survivors. It is the unthinkable," said campaign manager Jeff Blodgett.

On board with the senator were his wife, Sheila, his daughter Marcia, three campaign workers and two pilots, transportation officials told Fox News.

Wellstone, 58, was running for re-election against former St. Paul Mayor Norm Coleman. The race was watched across the nation as one of the contests that could determine the majority party in the Senate.

Wellstone, considered the most liberal senator in Congress, was headed from St. Paul to Eveleth-Virginia Municipal Airport northwest of Duluth in a chartered twin engine Beech Air King 100 turbo-prop, said to be one of the safest planes in the air.

The family was on its way to a funeral for the father of a state senator at the time.

The plane lost radio contact with the tower at 10:21 a.m. local time and crashed two miles from the runway, according to National Transportation Safety Board officials.

Freezing drizzle and light snow had been falling and there was light fog, but officials are not certain that contributed to the crash.

There had been concern that Sen. Ted Kennedy, D-Mass., was on the plane as well since he was campaigning for Wellstone, but it has been confirmed that he was not.

Wellstone announced recently that he had been diagnosed with multiple sclerosis, but said he would not let it deter him.  Before he acknowledged his disease publicly, denizens of Capitol Hill had noticed that he was walking with a limp.  He chalked it up to long work days.

The old-school traditional Democrat had broken a term-limits promise to stop running for office after two terms, saying that Minnesota needed a voice of opposition to the Bush administration.

Wellstone was adamantly opposed to a recent resolution giving the president the authroity to use military force in Iraq.

However, by all accounts, he was considered a man of incredible integrity and one of the most straight-forward and honest brokers in the Senate.  Observers say he would never look at poll numbers to determine his policy positions.

"He never blinked," said former Republican Rep. John Kasich, who added that dying while serving one's country is "the ultimate sacrifice."

"It's pathetic that he would have to die" this way, said Sen. Pete Domenici, R-N.M, who had been working with Wellstone for a Mental Health Parity Act for about three years.

The bill, which would give mental health conditions the same insurance protections as physical conditions, will be dedicated to him, Domenici said.

This is the second election in a row where a Senate candidate has died in a plane crash.  In 2000, former Missouri Gov. Mel Carnahan, his son and campaign workers were killed in bad weather.  The governor of Missouri appointed his widow Jean Carnahan to fill the seat he won posthumously.  She is now running in her own right to fill out the last four years of the term.

According to Minnesota law, the Democratic party could nominate a replacement candidate to run.

If Wellstone wins his election posthumously, assuming his name remains on the ballot, Gov. Jesse Ventura, an Independent, could call a special election to replace him or appoint a Democrat in Wellstone's place.

Minnesota's senior senator, was born to Russian immigrants Leon and Minnie Wellstone on July 21, 1944. In 1963, Wellstone married Sheila Ison, his high school sweetheart. They have two surviving children, David and Mark and six grandchildren.

Wellstone was a college professor before running for office, campaigning across the state in a green school bus.

Fox News' Carl Cameron and Rita Cosby contribute to this report.