This happened in Arizona on the Merkle Memorial trail in Usery Mountain park. Authorities still haven't released the species involved, probably Africanized bees, but it's possible it was the less aggressive European honeybees.
https://www.washingtonpost.com/news/...-in-ariz-park/
...just before 9 a.m. when he and a friend were suddenly attacked by thousands of bees.“Without provocation or warning, a large swarm of bees descended on both of them as they continued on the trail,” the Maricopa County Sheriff’s Office said in a statement.
Bestler’s friend, identified in the statement only as Sonya, was ahead of him on the trail. She was able to scramble to a restroom to escape the swarm.
When Sonya alerted another hiker to the attack, the man went back to check on Bestler only to find him at the center of a thick, dark cloud of insects.
“Alex was located lying on the ground still covered by bees and he was not able to approach due to the aggressiveness of the bees,” the statement says.
When park employees arrived, they, too, were “forced back by the bees.”
As the swarm stung Bestler over and over again, rescuers tried to reach him several times but couldn’t get close before they were driven away by the insects.
Finally, Allen Romer arrived to the park. The MCSO sergeant jumped on a park utility task vehicle, or UTV, and raced to Bestler’s location.
“With the assistance of two Rural Metro Fire Fighters, Sgt. Romer was able to load Alex onto the UTV and remove him from the scene, still covered with bees, and a swarm pursuing,” according to the statement. “Upon arrival at the emergency vehicles’ location, the bees had dissipated to the point of safety, that fire personnel began life saving measures.”
Bestler was whisked to Desert Vista Hospital but not in time. He died after arrival.