Former homeland security chief visits tunnel after terror attack: 'We're not afraid'

— -- Former Homeland Security Secretary Jeh Johnson has a message for would-be terrorists: "We're not afraid."

Johnson spoke with ABC News at the scene of Monday's terror attack in an underground passageway near the Port Authority Bus Terminal just blocks from Times Square. Five people suffered minor injuries in the attack. The bombing suspect, Akayed Ullah, 27, was badly injured from the explosion and has been charged with five federal counts, including use of a weapon of mass destruction and bombing a place of public use.

Today, Johnson, who served as DHS secretary under President Obama, confirmed that the Port Authority passageway was part of his daily commute. When the pipe bomb partially exploded Monday, Johnson said he happened to be walking above ground in a break with his normal routine.

"Today, I wanted to make a point of coming through this subway at this specific passage, at this time to demonstrate what a lot of New Yorkers are demonstrating -- which is that events like this happen, but we're strong, resilient," Johnson said. "We're not afraid. It's important to show that terrorism cannot prevail."

According to the charging document, Ullah made statements to police that indicated he “was inspired by ISIS to carry out” the attack and said, “I did it for the Islamic State.”

Ullah allegedly detonated a homemade pipe bomb during morning rush hour around 7:30 a.m. The charging document said law enforcement personnel found a 9-volt battery inside Ullah’s pants pocket, wires connected to the battery running under his jacket and fragments of metal pipe. There was also a remnant of what appeared to be a Christmas tree light bulb attached to the wires.

Jonhson went on to say that the incident underscores the need for public vigilance.

"Terrorism can strike at any moment," Johnson said. "Yesterday's event reflected the current threat environment: so-called terror-inspired attacks by lone actors," he said. "'If you see something, say something' is more than a slogan."