Complex sentence: Zoopark's drummer Valeriy Kirillov states that he did die because of cerebral hemorrhage, but the reason was not a natural cause but fracture of the skull base which Mike received during a robbery near his house.
Split into simpler sentences: Zoopark's drummer Valeriy Kirillov states that the reason was cerebral hemorrhage, but it wasn't a natural cause. The real reason was fracture of the skull base which Mike received during a robbery attack near his house.