Authorities in Northwood are investigating the death of a Charles City man who was being detained on suspicion of beating a woman. The Worth County Sheriff's Department responded to a report Sunday night of a possible domestic assault at a home in Northwood. A deputy entered and saw 39-year-old Michael Lee Zubrod severely beating a woman. The Iowa DCI says additional deputies arrived to subdue him. While Zubrod was handcuffed, he became unresponsive and was later pronounced dead. The 48-year-old woman was airlifted to a hospital in Minnesota for stab wounds and blunt force injuries. She was in serious condition Monday night. The state Medical Examiner's Office conducted an autopsy on Zubrod and results are pending.