COEUR d'ALENE - It's called verticillium wilt disease.

What it is, is a death sentence in the world of trees.

Where it is, is Bluegrass Park in Coeur d'Alene.

What can be done, unfortunately, is very little.

"Once a tree gets infected, it can live for a few more years," said Katie Kosanke, urban forestry assistant with the city, on the life span of a stricken tree. "Unfortunately, there are no treatment options."

Already, 10 sugar maples at the 11-acre park have been pulled because of the disease, which survives in cultivated soil and spreads from tree to tree beneath ground along root routes.

But even removing trees won't cure the park of its problem. As the fungus survives underground, there's no telling how far it can or will spread.

"It can be transferred through the roots because the root system grows wide and not deep," Kosanke said.

Like fingers from different germy hands reaching out and touching each other, so is the avenue to spread below the surface.

The city suspected the problem about a year ago when it noticed limbs on trees dying off individually. That's how the disease works, it inhibits water intake for trees so branches slowly wilt away one by one. As the pattern persisted, the suspicion grew. Conformation finally came a couple of weeks ago after a forest pathologist examined samples.

Count disc golf enthusiast Gerald Parker among those who don't want to see the disease spread and more trees die. He tosses discs at the Bluegrass Park course two or three times a week, and noticed at least one of the trees had been removed, because it had been a landmark around which golfers had to navigate.

"It's an enhancement to have all the trees," he said. "It makes you become skilled and accurate."

It costs roughly $300 for the department to remove and replace a tree.

If the bad news is there's no cure for the disease, and no telling how far it can spread, the good news is not every species is susceptible. The city's parks department works with 66 different tree species around town, so it will replace lost trees this fall with a fungus-proof stock, probably of the oak or fir variety.

Nearby neighbors have been notified.

Meantime, the best way to prevent the disease is to keep nearby trees healthy, as, just like with humans, the healthier variety are more likely to resist a disease. Another thing arborists can do is sterilize pruning equipment after each use. If tools have touched an unhealthy tree, they can spread the disease when the contact a healthy one.