Investigators have learned more about the death of a northern Iowa man. Jeff Jacobson, a Special Agent with the Department of Criminal Investigation, says the death of 41-year-old Michael Lee Ruberg is being treated as a homicide.

Jacobson says the state medical examiner has ruled Ruberg died as a result of blunt force trauma. A Humboldt County Sheriff’s Deputy found the Dakota City man’s body early Saturday morning after a 9-1-1 call about a man "down on the street" in the town of Rutland.

Jacobson says emergency workers tried to revive Ruberg, but he was pronounced dead at the Humboldt County Memorial Hospital. No one has been arrested in the case, but authorities continue to question witnesses.

"There was a confrontation between (Ruberg) and another person, but the investigation is continuing, so as far as what (witnesses) have said…that would be confidential at this point," Jacobson told Radio Iowa.