CUMMING — He was almost finished with his Otwell Middle School bus route when a “large green blob came out of nowhere.”

That was the only description the bus driver could give Forsyth County Sheriff’s deputies March 3 to explain why his driver-side window suddenly shattered as he traveled south on Dahlonega Highway. And it wasn’t even close to St. Patrick’s Day.

According to a sheriff’s report, 19-year-old Nicholas Allen Jones of Cumming was arrested after he apparently threw a mint chocolate chip milkshake at the bus.

Jones told deputies that he and a friend had been at Steak ’n Shake prior to the incident, and the friend had bet him he wouldn’t throw the dessert at a moving vehicle.

A witness who had been driving behind Jones’s white pickup truck since the Market Place Boulevard area reported that he saw the vehicle “swerving all over the road.”

Jones said the cup was less than half full. He was allowed to call his mother and write an apology letter to Forsyth County Schools for damaging the bus before being charged with first-degree criminal damage and the disruption of public schools.

He posted an $11,715 bond from the Forsyth County Detention Center later that day.

The bus was carrying some 30 students when it was hit about 4:30 p.m., according to Robin Regan, a spokesman for the sheriff’s office.

Jennifer Caracciolo, spokeswoman for the school system, said the driver pulled into nearby Cumming Elementary School, where the students were transferred to another bus and taken home. No one was injured.

According to Caracciolo, the damage to the bus was minimal.

“The window was replaced that evening and [it] was back out on route the next day,” she said.

Jones is not enrolled in the school system.