Consider cabling or bracing weak forks or branches in older trees of high value. This is work or a professional arborist. Do not plant trees with narrowly-forked stems. Where a high value tree may be suspected of developing into a hazard, use landscaping to keep people at a safe distance. This may require techniques such a re-routing walks, moving patio furniture, or planting shrubs and hedges as barriers to foot traffic.
Prevention is the best solution to the tree hazard problem.
This document is Fact Sheet DH 102, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611. It was originally published by the National Arbor Day Foundation.