Thousands of angry bees have attacked a man in a wheelchair, sending him and three others who came to his aid to hospital.
The attack in the southern California city of Santa Ana also shut down a street and forced the evacuation of several businesses while beekeepers removed the hive, which was estimated to contain 60,000 bees.
The trouble started at a storage yard when the man in a wheelchair apparently disturbed the hive, causing the bees to attack him, Santa Ana fire captain Steven Snyder said.
"He was attacked and stung over 60 times and had fallen out of the wheelchair and was yelling for help," Capt Snyder said.
The man's cries attracted the attention of three bystanders who ran to his aid. The bees were so aggressive that the three men had to retreat initially, but they dived back in and managed to pull the man to safety, Capt Snyder said.
He said the men were stung dozens of times during the "very impressive" rescue, adding that: "They probably saved his life."
All four men had difficulty breathing and suffered rashes, nausea and vomiting. They were taken to hospital and at least two of the men were released on Thursday night. Two firefighters who responded to the scene also were stung.
DNA tests are planned to determine if the bees were Africanised because of their aggressive behaviour. Africanised bees are a hybrid strain of honeybee distinguished by their aggressive traits.
On Wednesday, Africanised bees swarmed several farm animals and killed a pig at a farm in Bisbee, Arizona. A pregnant sow was also stung so many times that it went into a coma and lost its litter.
In northern Arizona, a 49-year-old man remained in hospital after authorities said he disturbed bees nesting under a cattle trough on Sunday and was stung more than 1,000 times.