San Diego's Vault PK is usually packed with bouncing and flipping children on Saturday evenings, when it hosts a "kids' night out" for budding athletes ages 5 to 14.
This past weekend was especially packed, parents said, as people cashed in a Groupon that got three kids into the parkour facility's open gym for just $30. The three-hour event is supervised by Vault PK staff members, so it doubles as a parents' night out too.
Some of the nearly 150 children present played on the America Ninja Warrior-styled obstacle course, but roughly a third had gathered on a 10-feet-by-30-feet wooden viewing platform, parent Cory Brizendine told San Diego ABC-affiliate KGTV.