One vacant, five bedroom home in Concord was about to become party central.
"When I came home, the front door of the house was open," said neighbor Michael Chavez.
Chavez says the police showed up just as carloads of teens began cruising by the house. The party was obviously a bust, but Chavez says he saw what could have been.
"All night, literally until like 2 in the morning, there were cars, probably more than 30 or 40 coming through here full of kids," said Chavez.
A search on a social website called "Topsy" shows several text messages and tweets telling everyone about a party in Concord. It was supposed to start at 9:30... BYOB [bring your own beverage]. Chavez says the police told him it's a popular trend where vacant homes are turned into party homes for profit.
"And they'll charge $5 to $10 a head for kids to come in and party. And kids will come in from all over the area, Antioch, Pittsburg, all over... and crash the house, destroy the house," said Chavez.
"When I got here I noticed my sign was kicked down. I went around the house. The back door was actually open," said realtor Ray Marquez.
Marquez is trying to sell the house. He says the house is set to close in one week and a major party, could have cost him the deal.
"Number one, the buyer would not want to close. Number two, the bank wouldn't pay for anything, it's an as-is sale and number three, the seller -- anticipating a short sale -- would have ended up getting a foreclosure on her record. So it really could have put a big damper on this whole process," said Marquez.
Some neighbors say they saw few teens scatter when the police first showed up, but no arrests were made. This is a problem that's been happening across the country and it's being fueled by the housing meltdown.