It was about 8:20 Monday night when the staff at the Byron Boys Ranch took a head count and discovered they were one short.
"This is an unlocked facility. It was at a time during showers and free play. It's not locked so it's easy for them to walk away if they want to," said Chief Deputy Probation Officer Paula Hernandez.
But the kid who escaped made law enforcement nervous enough to tell residents that he was on the loose and they should shelter-in-place.
"He was in for a violent offense and therefore we thought it was important to notify the residents in the area through a telephone emergency notification," said Contra Costa Co. Spokesperson Jimmy Lee.
About 20 minutes later, three more boys walked out of the facility unnoticed. Administrators think they were probably influenced by the fact that the first boy had successfully slipped out.
"I was surprised and disappointed and I was concerned that the other youth in the facility were okay, that we check on their welfare. I was actually surprised that one youth left and then three left after that, because normally they all go together," said Hernandez.
In fact, it's the first time long time employees can remember four ever leaving all at once. Residents of Discovery Bay say the warning of the loose offenders was a bit unnerving.
Administrators say the kids at this facility are low level offenders -- kids who commit felonies such as murder and rape are not allowed here. They say the lack of locks is an important part of their treatment.
"Historically the youth will stay here and participate and it's not our intent to oppress or demean them," said Hernandez.
Because they are juveniles, authorities won't release much information about the boys or their offenses. The boys are 14 and 15-years-old. The administrator at the ranch felt confident they will be caught, but said when they are, they will not be returning to the ranch.
Anyone with information regarding the boys' whereabouts is urged to call the sheriff's office at (925) 646-2441.