More than 40 people from schools and other institutions attended a Nassau County Police Department seminar Monday on how to prepare for a gunman being loose on their premises.
"You must have a plan. You have a fire escape and a plan for a fire; you need one for this as well," Police Commissioner Thomas Dale told his audience at Hofstra University's Monroe Hall in Uniondale.
This was the department's third briefing on the issue for schools.
For the first time, the invitees also included hospitals and big businesses, such as Cablevision, which owns Newsday.
None of the general businesses attended, but four hospitals sent representatives.
Clips from Columbine and Virginia Tech were shown, as well as a short film of a mock county police response to an "active shooter" at a school.