The parking lot of a Target in Wilsonville, Ore., has become a mass grave for thousands upon thousands of dead and dying bees, according to the Corvallis Gazette-Times.

It is not known for certain what exactly lead to the death of the black-and-yellow bumble bees but scientists are guessing that the trees were sprayed with an insecticide that kills bees.

Rich Hatfield, a biologist with the Portland based Xerces Society for Invertebrate Conservation was called to the scene after shoppers reported the event. Hatfield estimates that at least 25,000 bumble bees were dead in the parking lot, according to the Corvallis Gazette-Times.

"When I was here Monday, it was even more dramatic than it is today," Hatfield said. "There were bees raining out of trees."

Mace Vaughan, also with the Xerces Society, spoke with KATU about the bee massacre.

"Losing 25,000 or more bumblebees - we've lost a hundred, a hundred and fifty colonies at least just from this area - just wiped them out," Vaughan said. "I've never seen an incident on this scale."

Vaughan and Hatfield gathered the bodies off of the pavement and placed them in test tubes so that they could to testing to figure out what exactly killed the bees. While they think that the cause is most likely insecticide there is a chance it may just be from the pollen of the trees, European Linden trees may be naturally toxic to bees, according to CBS News.

"We can't say for sure that it is something they put on the trees," Hatfield Said. "These trees are European Linden trees, which have been known to be toxic to bees."

Even though bees tend to be feared by people for their stings and the horrible allergic reactions they can cause in some people they are still an essential part of our environment, in particular bees have an enormous effect on our food supply. It remains to be seen what the loss of the hundreds of colonies will do to the ecosystem in Wilsonville.

The Huffington Post has a gallery showing all of the devastation.