An update to a story CJAD told you about last week about thousands of dead and dying fish in the lake at Angrigon Park.

The city says it's a natural occurence but it's never seen things this bad.

Denis Fournier, a city spokesman responsible for wildlife and parks, says the fish died from a lack of oxygen in the water. He says while it is normal for some fish to die every winter, he has never seen the impact this strong.

"And the thickness of the ice on top of the lake this year is particularly thick this year," he explains, "which leaves very little water underneath."

As for why the fish have all gathered in one small part of the lake that isn't frozen over, Fournier says it seems they were trying to find air but the water is just too low. 

He says they've tested the water and it is not contaminated. They are trying to find solutions now to avoid this situation and prevent so many deaths in the coming years.