Authorities are investigating after a small plane crashed Wednesday in southern Wisconsin, the National Transportation Safety Board said.

The NTSB said in a tweet that it is investigating the crash of a Mooney M20R aircraft near Watertown, a city in Dodge and Jefferson counties about 48 miles northwest of Milwaukee.

Later, the Watertown Police Department confirmed that it was a fatal crash. 

Television helicopter footage from the scene showed apparent aircraft debris spread across a field and in an adjacent wooded area.

Mary Bellows, who lives in Watertown, told the Milwaukee Journal Sentinel that around noon she heard the plane and then a big boom. She said her room shook, and then a large plume of smoke rose near her home.