There's a lot of work that goes into determining whether or not a tree is safe and healthy.

After the tragic and sudden death of 35 year old Brian Costantini, who was pinned by a fallen 80 foot oak tree while golfing at Mill Creek park, officials there said that tree was actually alive.

So how do you know when it's time to get rid of a tree and how can a perfectly healthy one just come tumbling down on a warm, dry day? Experts tell 21 News there's no one straight answer.

"You get an ant or an insect such as emerald ash borer and eats the tree and that tree's weakened from the inside out, then you can't really tell from looking at it," said Matt Baird, owner of Baird's Tree Service.

Then there's underground factors at play, also not seen by the naked eye like, "root rot and soil stabilization, improper planting," said Baird.

However, in the case of entirely healthy trees, officials say other factors like storm winds from another day could have started the uprooting process and eventually the tree just falls.

Mill Creek Metroparks Executive Director Aaron Youngs says because of how many trees are in the metroparks as a whole, park staff don't just go around checking all of them but if concerns are raised about a certain tree, they will act.

"If they're out and about performing their duties, they see a tree of concern due to it's proximity to users within the park they need to take another look at that, or even we need to remove it right away, they'll identify that," Young said.

Since the tree that fell was deemed healthy, Young says there is no investigation into how it fell and they are considering this an act of God at the moment.