Update: Not looking good… dead wood in the middle came right out. The gash is about 6” deep on a 14” or so diameter trunk.

That tree, looks like a Linden, is almost certainly hollow inside. The gash in its side which became dead was probably due to a lightning strike some time ago. The outer live wood is curling inward around the open gash hole.

Get that tree removed ASAP. It is really dying....but doing so slowly. Removing a tree is not a handy man's project. Get an expert. Shop around. Go to Angie.

Getting that tree removed will be one of the smartest things you will have done for your family.

Moses

Thanks for the info. It is a Japanese Maple if that makes a difference

It looks pretty bad. The heartwood is rotted out completely and as mentioned, could've been struck by lightning, or something else.

What's happening is the outside sapwood and cambium layers are still alive, and they will add a new layer of sapwood to the hollow trunk year after year. Depending on how long it has been this way will determine how strong it has become since the damage was done. Sapwood does harden off, turning into heartwood after a few years and hollowness is not an unusual trait for many trees that are many years old.

If it falls, it will be most likely during a storm with strong winds so the biggest concern is, if it falls will it damage anything valuable?

A tree 14" diameter can be removed if you have any experience about these things and have the equipment/tools to do the job.

The biggest danger in a residential area will be power lines one might encounter. Or if the tree is tall enough to fall on something of the neighbors, past your yard perimeters.

If you have a pole saw and can start at the top, removing smaller upper portions of the branches in pieces, is the safest way, until the tree is short enough it can be dropped within the area around it.

If it's larger than it appears in the picture, then some certified help would be in order.

A picture of the whole tree would help to see what things look like.

Japanese Maples can be amazingly resilient in terms of growing past prior damage. That being said, this tree should be considered doomed. But if you desperately need the shade of it to shelter your, oh I dunno, collection of rare hostas - and it isn't leaning over a part of your house - sure, there's no harm in leaving it there a few more years while something else grows up in its place. I have a situation like that now, a JM that was injured by the hayseed teenaged lawn guy I inherited with this house. He had a habit of bumping trunks with the edge of his mower deck! It's been rotting from the inside out for what, 16 years now, and refuses to fall, but I wouldn't hold a picnic under it, either. I am pretty sure it will last another 3 years or so. A Glyptostrobus is going to replace it for shading a group of rhododendrons,

Somehow I can't see a Japanese maple come crashing down causing havoc.

If it were a japanese maple or even Cornus florida dogwood type tree I'd probably leave it unless the location was just legendarily bad like above the chair you rock the baby in during thunderstorms bad.

Now a red maple, Acer rubrum can get bigger and come damaging cars easier.

Do you still have any foliage to post a pic of and confirm the ID?

Oldsfan, I also wondered about identity. Only seeing what looks like oak leaves on the ground.

Yes, if it's oak, it would be a lot stronger sooner than linden or soft maple.