JEFFERSON, S.D. (KCAU) — A morning structure fire near Jefferson, South Dakota has been ruled as accidental according to the Union County Sheriff’s Office.

Firefighters were called to a residence in the 48000 of 332nd Street, about two miles south of Jefferson, South Dakota, Monday around 7 a.m.

When crews arrived on scene, the structure was fully engulfed and multiple crews including North Sioux City Fire Rescue provided aid.

No one was home at the time of the incident. The South Dakota Fire Marshall determined the cause to be from mechanical failure.