The West Virginia Division of Natural Resources says necropsies show that hundreds of birds found dead at Tucker County High School last month died from crashing into the building.

The agency said Friday 494 birds, most of them warblers, died after they became disoriented in fog and crashed into windows and walls. While the agency says some birds possibly died from exhaustion as they ceaselessly circled the school, carcasses collected from the grounds had trauma such as hemorrhaging and fractured skulls, wings and legs.

The DNR is working with the Tucker County school board and Allegheny Power to make the site less attractive to birds.

The DNR says 31 different species were involved in the bird strike. More than 80 percent were identified as warblers.