The mother of a Montana man found dead at a western North Dakota oil well is suing the well’s owner.

Trista Juhnke (JUHNK’-ee) filed the wrongful death lawsuit against Marathon Oil Corp. last week in district court in Montana’s Yellowstone County. Junke’s son, 21-year-old Dustin Bergsing, of Edgar, Mont., was found dead on Jan. 7 at the well in Dunn County. Bergsing worked for a contractor at the site, not Marathon.

An autopsy found Bergsing died from inhaling petroleum vapors.

The lawsuit alleges Marathon was negligent in inspecting and maintaining the well site. The lawsuit seeks unspecified damages.

Marathon spokeswoman Lee Warren said Thursday that the company had not received the lawsuit.

The company has said there were no apparent problems at the site.