CLOSTER, N.J. (CBSNewYork) – This week’s powerful storm knocked down trees across the Tri-State Area, killing five people.

Experts say a few safety tips could prevent future tragedies. CBS2’s Vanessa Murdock found out how to tell if your trees might be in trouble.

Trees were shredded, twisted and toppled by ferocious winds Tuesday.

On Thursday, the scream of a mulching machine echoed through the normally quiet Oradell neighborhood as crews worked to clear what’s left of Ed Spreckelsen’s old maple.

“This one apparently was a little rotten in the middle. You couldn’t tell from the outside,” he told Murdock.

Or could you?

“How do you know when a healthy tree is going to fall down because of a wind burst?” one viewer asked Murdock, so she asked an expert.

“It’s the weak ones that get culled out by the wind,” said New Jersey state licensed tree expert Ken Barber, of Ken’s Tree Care. “We can’t do an X-ray of the tree, so we’re looking for external factors.”

In some cases, a glowing, green canopy gives the illusion of safety. When in fact, your beloved red oak could be crumbling at the roots.

Barber said there are three things he looks for: long cracks in the trunk, big cavities and fruiting bodies of mushrooms at the base. Murdock spotted some on one casualty of Mother Nature with a root system more than 10 feet wide. Still, it was no match for the fungus chowing down on the tree.

Barber said of all the trees he inspected that came down during Tuesday’s storm, 85 percent were structurally unsound.

“Pretty rarely do you get a perfectly healthy, beautiful tree falling over, so let’s not go out and cut down the trees,” he said.

Instead, he said, asked a trained eye to take a look, adding most licensed tree experts will do it for free.