It’s probably an HOA pool,
and some neighborhood kids either invited
people from outside the neighborhood
or leaked the gate code.
I read (for what it’s worth) that there was a party with a DJ and the DJ was tweeting for people to come and they did. I also read juveniles were jumping private fences and getting into residents’ pools. Sounds like a lot of “youths” behaving like “youths”.
In other news:
Summer Jam concert erupts into chaos as agitated crowds try to get in
A hip-hop and R&B concert in New Jersey erupted into chaos Sunday night when police in riot gear tried to contain agitated crowds.
The melee started when attendees tried to forcefully enter the Summer Jam concert at MetLife Stadium in East Rutherford, authorities said.
http://www.cnn.com/2015/06/07/us/new-jersey-summer-jam-chaos/index.html
Still more “youths” being “youths”.