"That sense of fear that people have now, maybe they didn't before," Glenna's mom Anne Putyrski added.

"I'd say that we as a nation are not as arrogant about our own security as we were perhaps 20 years ago," Dale said. "And I think we have a better heightened awareness, and are maybe more vigilant."

Dale also noted that the 9/11 attacks helped galvanize the country and bring the society together, but it didn't last long. "Now 20 years later, I see a country that's largely divided," he said.