A tractor trailer carrying millions of bees overturned while driving down a Delaware highway on Tuesday, freeing the bees and causing a massive swarm that shut down the highway for hours.

The tractor trailer was delivering nearly 460 honeybee hives from Florida when the vehicle overturned on the northbound ramp of 896 to northbound I-95 in Newark at around 6:10 p.m., CBS Philly reported. The crash freed approximately 16 to 20 million bees, forcing authorities to shut down the ramp until around 7 p.m. Wednesday while the bees were removed.

"I was loading the car up over here and then I saw bees everywhere," Mike Gray, a tow truck driver, told the station. Mike was at the scene towing a car from an unrelated incident.

"I've seen eggs and chickens, but never a bee truck flipped over," Gray said.

The driver and two of the trailer's passengers were taken to Christina Hospital with minor injuries, including 50 to 100 bee stings each, the Associated Press reported. Other passersby in the area reported being stung.

Authorities cited the driver, Adolfo Guerra, for carrying an unsafe load or cargo, CBS Philly reported. He was delivering the bees to Maine to be used for pollination purposes.

Guerra was driving onto the ramp's turn when several wooden crates shifted inside the trailer and caused it to fall over on its left side and skid against the guardrail, investigators told the station. The bees escaped from their crated hives and flooded the highway.

The Delaware State Police Department had to implement the "Bee Swarm Removal Plan," where local beekeepers and fire crews were called to help disperse the bees with water. It was the first time the plan was used in 14 years.

Authorities are still investigating the crash, according to CBS Philly.