OMAHA, Neb. -- Four teenagers have admitted to vandalizing a Union Pacific Railroad signal box in Union, Neb., said Cass County Sheriff William Brueggmann.

Police arrested 18-year-old Stephen T. Onnat, of Omaha, and Edward V. Yohe, 18, of Lincoln.

Two other juveniles, ages 16 and 17, from Nebraska City, were taken into custody. Police released them to the Nebraska Health and Human Services.

All four suspects, who lived in foster care in Murray, Neb., were charged with felony criminal mischief and trespassing, Brueggmann said.

The signal box houses electronics that direct traffic on railroad tracks. The signals are used to either stop a train or allow it to continue on the tracks.