Here are several things to look for when assessing the risk potential of trees:

• Broken or dead branches 
• Limbs beginning to die-back from the ends
• Open cavities or rotten wood anywhere on the tree
• Mushrooms or other fungus growing anywhere on the tree
• Cracks or splits in the trunk or where branches are attached
• Have neighboring trees fallen over or died from disease?
• The tree is growing on a lean
• Many branches originating from one point on the trunk
• Damage to root system from landscape development, soil compaction, or digging
• Has the site recently been changed by construction, raising the soil level, or installing lawns?
• If the tree been topped or otherwise heavily prune