(KTLA) — An unfortunate mystery is playing out at a Los Angeles park where ducks have been found sick, dying and dead.

Those who live near Hollenbeck Park in the Boyle Heights neighborhood and others who visit on a regular basis say the discovery of the dead and dying ducks has been heartbreaking and concerning.  

“I usually come running here around the lake and, you know, sometimes you’ll see birds, but there’s just any number of them, like at least 15 or so just washed up on the shore,” said a woman who didn’t want to give her name.  

She said she first saw the ducks Saturday, and when she returned to the park on Sunday, she said, there were even more — five of them that were dead and a sixth one that was struggling to survive. 

Margarito Garcia was visiting the park and noticed a goose hovering around the dying duck, seemingly protecting it.  

“I come every weekend to walk my dog through here,” he said. “Unfortunately, it looks like someone has been poisoning the ducks, I think, because they are dying slow.”  

It’s unknown what’s causing the ducks to fall ill. Several people who spoke to Nexstar’s KTLA said they have reported the dead birds to animal control but haven’t received a response, likely due to the holiday weekend.  

Howie Berkowitz, founder of the Duck Pond of Lake Elsinore, said there may be other issues at play that are causing the ducks to get sick and die.  

“One is that the water is actually contaminated and that could be either through someone has done that, or the other possibility is that there is poisonous algae out there, especially during the summer when the water gets hot,” he explained.  

Berkowitz, who has had his duck sanctuary for 10 years, added that any ducks that appear sickened need to be seen by a veterinarian right away.  

“The faster they can administer some activated charcoal, the faster it’ll stop the problem,” he said.  

Another avian expert who spoke to KTLA said there is cause for concern because the issue could be what is called avian botulism. In that case, a duck ingests a lethal bacteria and dies. Flies feed on the carcass, then other animals in the area feed on the flies, and the illness continues in that cycle until it is brought under control. The expert added that it’s impossible to know whether avian botulism is the problem until a necropsy is performed on one of the dead birds.

“Hopefully, it’s something small and people are not intentionally killing them,” one park visitor said.

KTLA has reached out to both the Los Angeles County Department of Animal Care and the California Department of Fish and Wildlife for comment.