Heavier limbs can snap and break apart due to high winds and the heavy weight of rain as trees grow. It is common for arborists to add cabling to trees to increase strength to any weak area of a tree. This helps to decrease the possibility of a limb breaking. Some species of tree just have weak limbs naturally that make it, so they’re more often due to just break regardless. When you see a steep angled “V” crotch in a tree, that tree is more likely to break than trees you see with a “U” shaped crotch.