The trunk had been largely covered in ivy, making it quite unobvious that it was about to fall. Once cleaned, the splits in the trunk were evident enough, and we started to remove branches.  Only when felled, however, could it be seen that there were finger-thick beetle borings in the centre of the trunk, either side of the splits in the timber. What is not so easy to determine is whether the splits allowed beetles in, or whether the beetle borings weakened the trunk, making failure inevitable. For the record, the wood appears solid and durable all around the beetle holes: not rotten.