A Target store in Wilsonville, Oregon was the site of a rare, deadly phenomenon on Friday.

According to the L.A. Times, around 25,000 bees were killed around the store and fell to the ground from trees, littering walkways and the parking lot, due to a pesticide that had been sprayed in the foliage. The trees surrounding the area were mostly lindens, which attract bees with their sweet nectar.

“It was a mistake to put it on linden trees in bloom,” said Dan Hilburn, director of plant programs with the Oregon State Department of Agriculture.

Bumblebees weren’t the only casualties; ladybugs, flies, and honeybees were also found in the parking lot. Workers placed protective netting over the trees to keep more insects from dying, but the EPA is investigating to determine whether the fault lies with the pesticide company–for mislabeling the product–or with those responsible for spraying the trees. Thousands of dollars in fines may be accrued

The warning label on the pesticide–Safari–reads, “This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area.”

An estimated 150 bumblebee hives were destroyed in the incident.