From saplings, Scott Wheeler helped trees grow at Kings Park in Newport.
"The majority of these trees in the park have actually been planted in the 19 years I've been with the city," he said.
But now, it appears someone is trying to kill them.
"There's definite evidence of the trees being poisoned," Wheeler said.
Wheeler said he thinks a total of four trees were poisoned, two last year and then another two last week.
"I'm quite sure that it's being done to open up a view shed. Waterfront views are very valuable and people care very much about them. We work hard to prune the trees up to create as much of a view shed as we can lower down, but the canopies of the trees need a place to grow," Wheeler said.
Newport police are now investigating.
"So many people pass through here. Somebody might have seen something that looked innocuous as it was happening but could have a serious effect," said Lt. Daniel Dvorak of the Newport Police Department, who was canvassing the park.
Each tree costs thousands to replace, but it's not the only cost.
Investigators are trying to figure out whether the trees are toxic and whether they are contaminating the bay.
Police said whoever is responsible could face vandalism charges.
"Most of all we want it to stop. We're committed. I'm going to be planting trees back here whether it's two a year for the end of time. So we're not going to give up," Wheeler said.