Best tip to survive a mass shooting

Security expert and former U.S. Navy SEAL Matt Maasdam teaches people what to do if they're caught in a mass shooting.

Speaking from Washington, D.C., in the wake of Monday's shooting at the Washington Navy Yard,Maasdam tells CBC's Suhana Meharchand: "Rule No. 1is to move. You have to move away from the threat.

"You want to get up and run away from that threat as fast as you can, and just keep running," he said.

Maasdam knows the Washington Navy Yard well, because he worked there just last year. He also worked as a military aide to the U.S. president.