BISMARCK, N.D. (AP) - Officials say an explosion at a newly drilled oil well in western North Dakota has killed two workers and severely injured two others.

The fatal fire was one of two oil field-related blazes reported in the Williston area Wednesday. The other was much smaller and no one was hurt.

Both happened in a part of the state that is experiencing what many are calling the largest oil boom in recent North American history.

The rig explosion happened around 5:40 p.m. McKenzie County Sheriff Ron Rankin said 21-year-old Brendan Wegner of Montello, Wis., died at the scene.

Regions Hospital in St. Paul, Minn., said Ray Hardy, of Mohal, died Thursday morning at the hospital.