Honeybees are disappearing, and scientists don’t exactly know why. Yet here’s where 20 million of them swarmed this week: on a highway ramp in Newark, Del.

A rig carrying 460 honeybee hives from Florida turned over at an Interstate 95 ramp on its way to Maine on Tuesday night. Police have cited driver Adolfo Guerra for unsafe transportation of cargo. He and his two passengers suffered 50 to 100 bee stings each and were taken by an ambulance to a nearby hospital. Others, including officers and passing motorists, were reportedly stung as well.

“We contacted beekeepers to assist,” Sgt. Paul Shavack told Delaware Online. According to Shavack, the swarms were so tremendous that they couldn’t “even get close to the truck.”

Following a “bee swarm removal procedure” that was used for the first time, the bee handlers worked with firefighters to spray water to disperse the bees. The beekeepers inspected the hives and saved what they could before the truck was moved. The ramp reopened Wednesday morning, 12 hours after the crash.

The seemingly huge number of bees at the accident site pales in comparison with the fact that about one-third of honeybee colonies in the United States have disappeared since 2006. This prompted scientists to declare an outbreak of colony collapse disorder, or CCD. Though the exact cause still spurs debate, the USDA Research Service and China’s Academy of Agricultural Science discovered last year that a pathogen called tobacco ringspot virus has been spreading in bees. More recently, Harvard researchers blamed pesticides used to grow corn and soy as a major driver of CCD. They believe that exposure to the chemicals causes memory, cognition, or behavior impairment in the insects.

As for the Newark accident’s salvaged bees, the unidentified bee handlers got to keep them.

“They were authorized to do that by the trucking company,” said Shavack.

This post has been revised to reflect the following correction:

Correction: May 22, 2014

An earlier version of this article misstated the accident’s location. It was in Newark, Del.