It began when one group of mostly juvenile lake-goers at Darlington County Park got into an argument that somehow involved another group.
Because Darlington is a county park, Bergen County Sheriff Anthony Cureton has officers stationed there during peak hours.
His officers responded to the dispute and summoned Mahwah police.
At some point, an unidentified sheriff's officer fired a blast of pepper spray that injured several youngsters and officers.
"Looks like a Mahwah police officer got the worst of it," one responder said.
An army of sheriff's officers and police from surrounding towns converged at the public lake off Campgaw Road and Darlington Avenue. Several ambulance crews were summoned.
In the end, it was believed only one person needed hospital attention.
At least 10 others went through a mobile decontamination unit that members of Ramsey Rescue set up at the park's entrance.
Some of the civilians were taken into custody -- including at least one juvenile -- and Mahwah police quickly had matters under control.
The lake was closed for the rest of the day.
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