US tree surgeon sent flying with chainsaw in hand when cutting large branch

This was the terrifying moment a tree surgeon in Boston, Massachusetts was sent flying with a live chainsaw in hand while cutting an unstable tree.

Footage captured on June 14 shows the tree surgeon atop a large tree while cutting a large branch.

While sawing the tree sways from its foundations swinging to one side sending the upper branch flying and the man swaying with the running chainsaw in hand.

The filmer, Shane Flanagan said: "A company is working to take down a large tree with compromised roots.

"The tree cutter is working to take the top part of the tree down, with tension from the ground helping to pull the top towards the empty ground.

"They underestimated how much they had pulled the tree over with the tension, and once the tree trimmer cut enough through the top, the tension snapped, flinging the tree back into a more straight position.

"This violent snap almost flung the tree trimmer from his place on the tree, all while a chainsaw attached to him was still running."