Similar to the laptop that travelers have to take out of backpacks and bags at the airport, one of the most forceful explosions came from what was called “an electronic device with artfully concealed explosive,” by Michael Walsh, supervisory transportation security specialist-explosive at Newark Airport.

Walsh, who’s worked for the Transportation Security Administration for the past five years after retiring from the New York City Police Department, gave students a first hand feel of how much explosive power the smallest article could pack, including replicas of improvised explosive devices such as the “Richard Reid” shoe bomb, the failed underwear bomb and a letter bomb.

Noting that the threat of terrorism extends to many different modes of transportation, Walsh said the idea is to give many levels of law enforcement officers knowledge about recognizing explosives and the potential for damage.

One of the points officials hope the demonstrations made was why travelers are restricted to bringing liquids and gels on aircraft in 2-ounce increments.

“The larger the container, the more harm can be done, so we discourage them,” Farbstein said.