Last week's devastating hailstorm, which damaged thousands of homes and vehicles in El Paso County, also killed more than 500 fish of eight species in Fountain Creek Regional Park's Duckwood Pond.
The fish didn't die from hailstones, but from quickly changing temperatures and oxygen levels during the storm, officials say.
The worst overnight storm in more than 20 years tore through the area early June 13, damaging and destroying windshields, roofs and trees in the Colorado Springs area.
At least 500 fish were killed in the pond, reported a Colorado Parks and Wildlife aquatic biologist who went to the pond Monday.
Parks and Wildlife stocked the pond April 30 with 254 rainbow trout, said agency spokesman Bill Vogrin.
Also killed were black bullhead, goldfish, common carp, European rudd, black crappie, bluegill and green sunfish, Vogrin said.
Th biologist determined that heavy rain and hail likely were responsible, he said.
"The unique and damaging storm we had last week produced large hail and cold rain in a short period of time," said Brian Bobeck, a county parks manager, in a news release. "The colder water temperatures mixing with warmer water can result in the pond turning over and depleting oxygen, resulting in fish kill."
Turnover - the gentle, natural mixing of layers of water in a lake or pond - typically is caused by changing temperatures in surface waters brought on by the progression of the seasons, says the University of Arkansas Division of Agriculture.
The university's website says: "So what causes a pond to turnover in the middle of the summer? It is usually tied back to a quick cool down from a rain event and is typically a smaller pond that will turnover. Most people do not realize their pond has turned over, unless there is a fish kill. Small, shallow ponds will be more apt to turn over in the summer months and have greater fish kill than larger, deep ponds."
The hailstorm didn't kill all fish in the pond, but officials don't know how many are left, Bobeck said. Most of the dead fish have been removed, and the pond is safe to fish in, he said.
Kids aged 16 and younger can fish there with a license.
"There's nothing wrong with the pond - it's just something that happened at that time," Bobeck said.
The pond is "considerably more shallow" than its counterparts in the park, county spokesman Dave Rose said, but he didn't know exactly how deep Duckwood is.
Fish in the larger, deeper Willow Springs Ponds farther north were not seriously affected by the storm, the county release says.
The storm also broke the park's restroom skylights and damaged its picnic pavilion roofs, Bobeck said.
"It's been a great amount of time, just doing cleanup," he said.