Something is killing bees in Oregon.

While the sharp decline in bee populations is not unique to the state, a recent mass death of honey bees has investigators involved. Last year, about 25,000 dead bumbles were found in a shopping center parking lot (later found to be the result of pesticide use).

The most recent incident was spotted in Sherwood, Ore., soutwest of Portland, along Highway 99.

Image source: KGW-TV

Image source: KGW-TV

Image source: KGW-TV

Image source: KGW-TV

Sherwood resident Danya Anderson was driving on Highway 99 when she spotted the bees.

“There were a bunch on the ground and a bunch swarming,” local resident Danya Anderson told KGW-TV. “Some were crawling and some were dead already.”

Pat Mitchell with the state’s Department of Agriculture Insect Pest Prevention & Management told the news station that an investigation, which includes taking samples, was launched after it received “calls of concern.”

Watch KGW’s report:

The news station noted that there are established hives and agricultural fields in the nearby vicinity.

Bruce Pokarney, a spokesman for the department, told the Oregonian that some hives are on property of an abandoned house.

“Who the heck do those belong to?” Pokarney said of the hives, noting that this is something investigators will nee to figure out as well.