A 56-year-old man from Willmar, Minn. was found dead in the Kandiyohi County Jail on Sunday after being arrested the day before on suspicion of drunken driving.

Kandiyohi County Sheriff Dan Hartog said deputies discovered George Edward Washington in his cell about 1:30 p.m. Sunday, unresponsive and not breathing. Deputies and paramedics were unable to revive him.

The cause of Washington’s death was not known as of Tuesday afternoon. An autopsy was being conducted, Hartog said, adding that there was “nothing suspicious in nature” about the death.

Hartog said his office would provide autopsy results when they are available.

Washington’s daughter, Quinshyra Grayson, of Marshall, Minn., said that her father had lived in Willmar for about a year. She said he was in his parked car with a friend on Saturday when police arrested him on suspicion of driving while intoxicated. He was taken to jail and his car was towed.

Washington called his daughter from jail Saturday night “and he sounded perfectly fine,” Grayson said. “He sounded like he did every day, because I talk to him every day.”

Grayson said police notified her Sunday afternoon that her father had died. A deputy told her that he had been “acting crazy” and was put on a suicide watch.

Ronald A. Edwards, a longtime Minneapolis civil rights activist who has spoken with the Washington family, said the family plans to seek a second autopsy.

He also questioned why no police report about Washington’s arrest has been made available. The family has been told there are cameras in the cell where Washington died, but it hasn’t been allowed to watch any video, he added.

Grayson said her father had an enlarged heart but hadn’t been in any recent medical distress.