LAKE OSWEGO, Ore. – Arborists say they hear it all the time. People in the Portland area who think the trees around their house are healthy. That is until a storm like the one on Friday rolls in and proves them wrong.

On Saturday, crews were using a crane to lift two fallen trees off a house in Lake Oswego.

“You realize how big they are. They’re cutting them into like 8-foot pieces but imagine how much they weigh,” said neighbor Al Nodarse.

Watch: Crews remove tree from Lake Oswego home

The Lake Oswego home was far from the only house damaged by downed trees during Friday’s deadly wind storm.

More: Powerful wind storm downs trees, causes power outages

But one arborist says one of the trees that fell on the Lake Oswego home was obviously unhealthy.

“This tree here had root rot,” said James Weiss with Rich’s Tree Services. “With the winds yesterday, it brought that out and the tree ended up coming over.”

The wind took that rotted tree down, said Weiss. On the way down, that tree hit another, toppling it too.

Fortunately, no one was hurt from these downed trees. But across the Portland area on Friday, that wasn’t always the case. One man died after being hit by a falling limb. In another case, a 12-year-old girl was pinned by a tree that crashed onto her home.

Photos: Wind storm topples trees across Portland region

Weiss said the majority of the time, even with winds as strong as they were Friday-, healthy trees don’t topple.

“Small issues that normally wouldn’t come up will when there are big winds,” said Weiss. “It’s going to bring out the Achilles heel.”

Weiss said the following are signs that a tree may be rotting and at risk of falling during a storm:

  • Conks, or mushrooms, growing from the base of the tree
  • Holes where branches may have fallen
  • Leaning trunk
  • Tree losing leaves from the outside in

In addition to regular self-checks, Weiss recommends having an arborist check your trees at least once a year.