My tree has died

[Mauro]

Hello

My front garden tree produced some beautiful blue flowers every year, it looks dead now.
Leaves are dry and brown, twigs are green (looks like because of moss) and there are cracks on the trunks.
How is this possible?
Last September I did cut a big branch that was touching the roof of my house, but this couldn't have killed it.
Another thing I can think about is last 4 months have been very wet in South London (where I live) and maybe the roots got waterlogger? I'm not an expert, just a thought, it seems very strange to me though.
I've attached some photos

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What do you think?

Regards, Mauro

 

[Tjohn]

It looks like you have an insect infestation that burrows into the tree. It takes a while to show up, but when it does, it seems like the tree goes overnight. I'm so sorry!

 

[Chuck]

If the leaves fall off the tree might still be alive, otherwise it's dead. Go to different parts of the tree, trunk, small branches, limbs etc and scratch the bark. If there is any green showing directly under the bark that part of the tree is still alive. For how long impossible to say. But by the looks of it I'd say it's time to start up the chainsaw.

 

[Mauro]

Thank you, however why do you think this happened?
I don't think I cracked the tree last Autumn even if I pulled it a bit trying to break the top branch that was touching my house.
In particular I see these splits all along the trunks and higher branches, googling I could find something similar called frost crack, is it?
Can this be due to the cold weather of 2-4 months ago?
I don't believe it was a lightening or somebody poisoning my tree

 

[Chuck]

That tree looks like a lilac, a common tree in the UK and in the southern US. They are a very short lived tree, living maybe 15-18 years. They are extremely cold sensitive. I think yours died of old age combined with the cold.

 

[Mauro]

Thank you Chuck, I think you are right