"Out of the corner of my eye just saw a tree split,” said Mounce, who was driving in Lake City.

He was trapped under the weight of the branches that landed on his Honda.

“I don’t know what the chances are of a tree splitting and falling on a moving car,” he added.

Experts say the chances of branches falling are, in fact, higher than usual because of the heat wave and drought.

Arborists call the phenomenon Sudden Limb Drop, or SLP, which can send otherwise healthy limbs to the ground.

"If he'd a been a half second sooner, the brunt of the tree woulda come down on the car, probably killed him,” said Steve Mounce, his father.

Seattle Department of Transportation says the tree did appear to have a structural problem already.

But, they said, the lack of rainfall probably made things worse.

"I'm just replaying the memory,” said Mounce, who has chest and neck pain but who is grateful to be alive.

His father wonders how something like this could happen.

"You shouldn't have to drive to work, and be afraid that a city tree is gonna fall on your car, period,” said Steve Mounce.