Hello

You are right to be concerned because the tree is so close to buildings and near where people frequently walk, etc.

The crack appears to be a lightning strike..

Tree risk assessment is a multiple factor, complex process that needs a trained professional arborist in “tree risk assessment”.

These certified professionals have been specially educated and passed certification tests.

They will look at health of the tree, tree species, etc, and look for signs of insects and disease in the crown, roots and bark.

The International Society of Arboriculture has a website where you can search for arborists in your area by zip code. Be sure to select one who lists “Tree Risk Assessment” in his/her qualifications.

http://www.treesaregood.org

Here are a couple references describing tree risk assessment in detail—-

https://www.extension.purdue.edu/extmedia/FNR/FNR-475-W.pdf

https://ucanr.edu/sites/Igor/Mature_-_Historic_Tree_Stands/Evaluating_the_Risk_of_Tree_Failure/