Crews responded to the scene, the Northwood Elementary School at 9805 24th St. East, at about 7:30 p.m. after receiving reports of a fire causing thick black smoke in the area.
Arriving at the scene, East Pierce County firefighters found playground equipment burning at the school. The fire was extinguished. There were no injuries.
An investigation found that the blaze likely was caused by fireworks.
It wasn't immediately clear if the Puyallup School District will be able to repair or replace the playground equipment in time for the start of classes in the fall.
Anyone who has information about the person or persons responsible for the blaze is asked to call the Edgewood police non-emergency phone number at 253-798-4721, then press 1.