A rollover collision involving six students brought a swift end to the annual "Nerf War" at Waconia High School, and marked the latest incident in the long-running battle to end the popular spring game in the metro area.

Nerf Wars, in which students form teams to "assassinate" one another with Nerf guns, ended the day it began in Waconia, shortly after sunset Friday. A compact car with three sophomores collided with a small sport-utility vehicle with three juniors at a residential intersection, according to a sheriff's deputy who is the high school's resource officer.

The sophomores had just finished a Nerf confrontation and were in pursuit of another, while the juniors had finished for the night and were dropping people at home. The SUV on southbound Oak Avenue had the right of way when the car, heading west on Sparrow Road, entered the intersection and struck the other vehicle. The SUV rolled and came to rest on the driver's side, and both vehicles had to be towed.

Witnesses said the car's driver "did not slow or stop," and he was ticketed, said Chief Sheriff's Deputy Jason Kamerud.

On Monday the sheriff's deputy and a school security monitor met with the six students, as well as the two seniors who organized the game this year. The two pledged that the game was over.

The Waconia Nerf 2018 Twitter account included a spreadsheet listing more than 40 teams with 300-plus members who paid $5 each to participate. The winner collects the kitty. Enrollment in the high school is around 1,100.

An SUV ended up on its side when it was struck by a car at an intersection in Waconia last week. Both vehicles' occupants had been out that day playing Nerf Wars.

On Friday, the Twitter account declared the conflict officially engaged: "Most importantly be safe, your real lives are more important than your nerf lives!"

The first hint of trouble came Friday with an all-capitalized tweet that the game was halted until further notice. Later came a tweet declaring the game over.

Superintendent Patrick Devine interrupted Monday night's school board meeting and made a nearly minute-long plea for parents to tell their teenagers to call a cease-fire.

"It's truly a dangerous game," Devine said. "So, I would have a conversation with your child ... they can really sell it as a pretty innocent game, but it's about chasing around in vehicles. It's really unsafe, and we don't want anything tragic to happen in our community."

Nerf Wars is an unauthorized rite of spring popular with students — and unpopular with school officials — coast to coast. The game is normally staged off campus in parks and other public places but has increasingly been infiltrating school grounds.

This spring authorities in nearby Chaska, Prior Lake and St. Louis Park issued warnings to teens about the legal and health consequences of the game.

Last week, Chaska police posted on Facebook a no-nonsense warning, prompted by "over a dozen complaints of illegal activity surrounding Nerf Wars." They went on to say that participants "are subject to any and all criminal consequences if they break the law. Consider this your warning. In years past, incidents related to Nerf Wars have resulted in injury, damage to property, and assaults in Chaska. In 2015 in Lakeville, it cost two young men their lives."

In December 2015, Lakeville South students Jacob Flynn, 17, and John Price, 18, were killed in a car crash while playing the game. Two other students were injured. No charges were filed in that crash. Parents of the young men killed sued the School District this year for failing to protect the teens from a known danger.

The Minnesota Chiefs of Police Association went so far last year as to issue guidelines for Nerf warriors, including to not play "in or near a moving vehicle, "never enter a home without permission, use only brightly colored guns that cannot be mistaken for actual firearms, and drop your Nerf gun immediately if approached by police."

The end of the Waconia game left organizers with a sizable pot to distribute. Students responding to a pop-up poll on the game's Twitter account favored donating the money to a food shelf, rather than giving refunds to the "living players."

One supporter said in a tweet that Friday's crash "I am thankful everyone is okay, but it really was special the way everyone in it came together after the crash!" The post was signed off with "#savenerf."