Hi! I noticed a rather large (nearly 5 ft long) and deep (about 12 inches) crack in my sycamore trunk this morning. The tree is about 15 feet from my house. Should I be concerned and tale it down? I hate to see it go, but don't want to chance it coming down on my house either. The tree is fairly old (an arborist told me its nearly 100 years, but it could be as young as 65 years). Thanks in advance!!