One person has been killed and several injured after a swarm of hundreds of thousands of bees stung several people in Arizona.

According to Mario Novoa, fire chief in Douglas, Arizona, landscapers at a house were attacked by the bees as soon as they turned on the lawnmower. A 32-year-old landscaper reportedly went into cardiac arrest after he was stung hundreds of times and firefighters were called to the house around 10:30 a.m. on Tuesday. 

"Apparently one of the workers was very close to the bees, the bees were located in the eaves of the home, just three feet away," he said.

Novoa said a total of seven people were stung, according to a report from ABC affiliate KOLD. Estimates of the size of the swarm range from 300,000 to 800,000 bees.

Lt. Joseph Alvarez, spokesman for the Douglas Fire Department, said the hive, estimated to be 10 years old, was found in the attic of a home where gardeners were working, according to ABC 15 Arizona

A beekeeper later exterminated the hive of bees, tearing off a portion of the home's roof in the process, according to a report from ABC News