Sen. Paul Wellstone died from the impact when his plane crashed last month, not from the fire that engulfed it afterward, a medical examiner said.

Dr. Thomas Uncini, St. Louis County's chief medical examiner, listed the cause of death for Wellstone and the seven others on board the small plane as "traumatic injury due to, or as a consequence of, an aviation crash with fire," the Pioneer Press reported Thursday.

The determination took several weeks because the bodies were severely burned in the Oct. 25 crash, Uncini said. He filed the death certificates Monday.

Uncini concluded that all the victims died from the impact based on blood analyses that found no carbon monoxide in the pilots' blood, meaning they died before they could inhale any smoke. The tests were conducted by a Federal Aviation Administration laboratory in Oklahoma City.

Earlier examinations of the plane's two pilots found no medical conditions such as heart attack or stroke, Uncini said. He added that he checked all the victims for gunshot wounds and there were none.

The plane crashed into a wooded bog while making its final approach to Eveleth-Virginia Municipal Airport in northeastern Minnesota, where Wellstone, 58, was headed to attend the funeral of a legislator's father. Everyone aboard the plane, including Wellstone's wife, daughter and three campaign workers, was killed.

Investigators haven't determined why the plane turned away from the airport, but other pilots had reported icing that morning. The damage to Wellstone's plane was too extensive to quickly determine whether its de-icing equipment was working, the National Transportation Safety Board said.

A final NTSB report on the cause of the crash isn't expected for several months.

Wellstone was temporarily replaced in Congress by independent Dean Barkley, appointed by Gov. Jesse Ventura. Republican Norm Coleman won the Nov. 5 election, edging out Wellstone's last-minute replacement, Democrat Walter Mondale.