Thousands of fish were found dead under the ice on Lake Owasso in Shoreview, Minn. because of what may be a lack of oxygen in the water.
The massive fish kill comes just before the ice fishing season and includes trophy-sized walleye, muskie and bass. The ice formed on the lake last week and many people that live nearby and fish on the lake have never see anything like this.
"I am sick to my stomach and worried this lake is connected to other lakes," said Jason Nelson.
PHOTOS: Lake Owasso fish kill
Neighbors noticed the fish kill on Thanksgiving and took pictures of the fish they pulled from the lake. They are at a loss to explain why so many of the fish are dying in such large numbers early in the season.
Some believe the fish are not getting enough oxygen – something that is a problem later in the winter. Others fear a chemical weed killer sprayed in the lake caused the fish kill.
"These are sport fish. This is one of the better fishing lakes in the area and we would like to know what the cause of the fish kill is," Nelson said.
Some people have tried to revive the fish by pulling them out, but they are usually too lethargic to swim away.
The Minnesota DNR is expected to come to Lake Owasso on Monday to take water samples and test the fish. They have oxygenated the water in the past, but that is typically done in the spring.