California ? Forget being glued to their seats: Kids at a suburban San Diego high school couldn’t even get through their classroom doors Friday.

With only a day to go before spring break, vandals plugged locks on all the exterior gates and doors on campus with super-strength adhesive.

“A teacher who always gets there early called me on my cell phone and said, ‘Guess what?'” said Carlsbad High School Principal Margaret Stanchi. “But I didn’t guess this.”

Roughly 100 doors were sealed shut sometime before the first staff arrived about 6:30 a.m., Stanchi said.

Custodial staff quickly unsealed the lock on a building with 27 classrooms, but the rest of the school’s 3,000 students were sent to sit in gym bleachers until their classrooms were opened, one by one.