LAS CRUCES, New Mexico -

Scientists confirm through genetic testing the colony of bees responsible for sending tree cutters to the hospital this summer in Las Cruces were Africanized.

Bee expert Carol Sutherland says tests confirm the bees were the aggressive hybrid, commonly referred to as "killer bees."

Crew workers were removing a dead cottonwood tree at the historic Alameda House when the bees began to attack. 

Emergency rescue crews had to shut down nearby roads and told residents to stay in their homes.

Two workers were sent to the hospital, a 52-year-old crew member had sustained hundreds of stings and was unconscious when paramedics arrived.

All of those who were stung have recovered.