A dog walker is lucky to be alive after part of a huge oak tree came crashing down where she stood on Hampstead Heath.

Faye Mansley described how she “ran for her life” after hearing a “crack like lightning” and looking up to see the huge trunk section hurtling down from above.

“I grabbed my dog and just ran and ran and did not stop until I heard it crash onto the ground. I was so relieved to get out of its path. My legs were shaking, like jelly,” said Miss Mansley, 39.

“I was so shocked. I sat down for a while. If I hadn’t reacted so quickly, I would be dead,” she said.

Once recovered, she went back to the spot to see what had fallen. “The tree was lying right across the path where I had been standing. I couldn’t believe how huge it was.”

She said an officer from the Heath constabulary was soon at the scene while a tree surgeon was sawing the trunk in half.

Miss Mansley, of Abbotts Garden, East Finchley, was walking her Patterdale Terrier Gary at Hampstead Gate, outside the Kenwood grounds, at around 1pm on Friday when the incident happened.

“I heard a banging sound and looked up. I was standing there, and then I heard a massive crack, like the sound of lightning and realised the tree was coming down,” she said.

Miss Mansley is now back walking on the Heath every day: “I made myself go back but on the first day I couldn’t even walk by a tree,” she said.

Dave Humphries, head arborist at the Heath, said: “A section of the oak tree, over 400 years old, came away from the main trunk due to internal decay.” The tree has been assessed and will be pruned. “We are satisfied the site can remain open to the public” he said.