They say there was a threat made on social media and was put on lockdown.
There are no new threats at the school.
Below is the message that was sent to parents at 3 p.m. on Wednesday, May 8, 2013:
This is an important message from the York County School Division. Due to a law enforcement investigation at Tabb High School this afternoon, Tabb High School students were delayed in dismissal. Tabb High students have now been dismissed from school as of 3 p.m.
As a result of the delay at THS, buses will be running at least one hour behind schedule at the following schools: THS, TMS, TES, MVES, BMES. Once again, bus routes for schools in the Tabb zone are running behind schedule this afternoon. Parent pickup will continue as normally scheduled.
Stay with NewsChannel 3 as more information becomes available.