"It's almost a lockdown for Syrians coming here," he adds.
The besieged city of Deraa has been in lockdown for a week.
The school was placed on lockdown for seven hours as a precaution.
San Diego Unified schools announced on Twitter that they remained on lockdown for under an hour.
An estimated 1m people in Boston have now been on lockdown for more than seven hours.
The eradication team remained in camp under a tight security lockdown for ten days.
Brussels has been under lockdown for three days, during which the underground network, schools and universities have been closed.
Hidden Valley Elementary School, located not far from the shooting, was placed on lockdown for nearly an hour.
Three schools in the area were put on lockdown for an hour while police searched for the suspect.
"It's been an eye-opener," said Amy. "People go into lockdown for a certain period of time.
Nor was Berlin closed down, like Brussels, which was in lockdown for three days during a terrorist manhunt last year.
