A swarm of Africanized bees killed a man and critically injured another man in Arizona on Wednesday.
The men were attacked while cutting grass and doing yard work for Douglas ARC, a nonprofit which finds jobs for people who are developmentally disabled.
Douglas Fire Department Fire Chief Mario Novoa said the two men where doing yard work for a 90-year-old homeowner, who was not injured in the attack, USA Today reports. Two other men doing yard work were also stung, but refused treatment. During the attack a neighbor was stung, but drove herself to a local hospital for treatment.
The bees came from a nearby attic that contained 800,000 bees in a 3-by-8 foot nest. While it remains unclear what provoked the attack, firefighters quickly blocked off a four-block radius, and police and firefighters wore protective bee suits while responding. The entire nest filled a 55-gallon drum once extraction was complete.
Novoa said that while most bee attacks in the area are from Africanized bees, there has been “nothing on the scale,” of this attack. (RELATED: Texas Man Stung Hundreds Of Times In Bee Attack)