Question
We have a very large old oak tree, it has had one limb a year break off for four years. These limbs are almost as large as a tree.  They are from one half, it is now a half circle of limbs on one side and none on the other. It is near our garage and the remaining limbs are on that side, I am afraid it is weighted enough to fall over now that all the weight is on one side, should we cut the tree down to be safe? Could the remaining limbs be pruned back. My husband loves the tree, I want safety.

Answer
Is the wood on the end of the limbs where it broke from the trunk hollow or mushy or not solid. This would indicate that a decay fungus has worked its way up the inside of the trunk and into the limbs causing them to break. Another indication would be where the old limbs had broken is the wound healed over with solid wood or is it mushy or hollow. If this is the case the tree would more than likely be classified as a hazard tree and at the least would need to be pruned or possibly taken down. BUT I would not do this without having a qualified person check the tree. I would start with checking with your local Forestry agency and ask one of their Foresters to come check and advice you or of there is one near you call a certified Arborist and have them check it. The State service is free and Arborist will charge. DO NOT have a tree service company make this visit they will advice to cut since thus is their business and most do not have the Technical knowledge to advice you. Here is a web link to the organization that certifies the Arborist so you can check for one in your area. Also here is some information on hazard trees that can be used when discussing the tree with those who may come look.

http://www.isa-arbor.com/findArborist/findarborist.aspx

http://www.na.fs.fed.us/spfo/pubs/howtos/ht_haz/ht_haz.htm