DENVER, CO -- Shattered glass, cracked tiles, stained ceilings.

Police say the damage is from teenagers who broke into a house and had a party. The Colorado homeowner says when he got home from dinner, the sheriff's department was there and hundreds of kids were pouring out of his home.

“I wish their parents could feel what this feels like. The violation…it's just shameful the party was posted online and deputies arrested some of the kids, “ says Mike Cox. His home was up for sale and he thinks the kids saw it online and thought it was vacant.

He had to pull it off the market because there's thousands of dollars worth of damage.

So if you're house is for sale - are there things you can do to keep people from breaking in? You can get a security system or just get security cameras.

Make sure there are signs around the house that say there's video surveillance. Motion sensor lights could also help.

Even if you aren't home, if that light shines, your neighbors could spot someone trying to break into and call police.