CAMBRIDGE, Mass. -- Prisoners were evacuated from the Middlesex Jail in Cambridge after a group of inmates allegedly broke the building's sprinkler system.

Middlesex County Sheriff James DiPaola said several inmates became unruly Sunday morning after 15 prisoners were sent to area hospitals with flu-like symptoms.

DiPaola said some prisoners broke the fire suppression system, causing the sprinklers to go off and flood the building.

“This group of inmates -- about 9 of them -- acted up in this one segregated housing unit,” said DiPaola.

The Cambridge Fire Department asked the sheriff's office to turn off the building's power, and officials began evacuating the inmates by bus to other facilities.

It was not immediately clear where they were headed, or how long the jail would be closed.

The jail, located over the county courthouse, originally was built to house 160 prisoners, but has housed up to 400.