He died from complications of a bad physical fall.
In a high percentage of cases, falls among the elderly result from alcohol or drugs. Unless you're falling off a ladder, (it's hard to imagine Ailes on a ladder), most of us have the reflexes to throw our hands up over our face and head and prevent a truly damaging fall. Otherwise, nobody would ever make it past the age of six-kids fall all the time. But their reflexes protect them from the worst. If alcohol or drugs are involved, those reflexes don't work as well.