Some say it will go down as one of the most devastating attacks on law enforcement in modern American history.
It happened when a man being served a warrant for possession of a firearm by a convicted felon opened fire, killing four officers and wounding another four.
Rich Vona, the director of law and safety at the Bucks County Safety Training Center, says those brave members of a US Marshal's Fugitive Task Force fully realized they were walking into a potential hornet's nest.
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"In this case, they were serving a warrant on a known person that they believe to have a firearm," he explained. "So, that would be a heightened level of awareness. It's not like you were serving a warrant for someone's computer."
Vona says officers are trained to look for ways to de-escalate heated situations but says what happened in North Carolina is an example of when a situation reaches the point of no return.
"There is no de-escalating that," he says. "That is what it is. You were going in at a deadly force level. Starts at the top of the 'use of deadly force continuum' and there's no de-escalating that."
Vona stressed that coming face-to-face with these types of life-or-death situations is not uncommon for law enforcement.
This past Monday night, police surrounded a home in Spring City, Chester County, for a domestic violence call that turned into a barricade situation with an armed man inside.
Shots fired at police during barricade situation in Spring City, Pa.
Fortunately, the suspect surrendered and no police officers were injured.
That's just one example of several such situations in the Delaware Valley over the past few years.
Vona says it all serves as a stark reminder of why our men and women in blue are often referred to as the bravest.
"The world is changing so fast, and the complexity of law enforcement's job changes every day. It's impossible to train for every aspect of every situation you'll get every single day. So, we simply try the best that we can," he says.
According to the Fraternal Order of Police, as of April 1, at least 98 officers across the country have been shot in the line of duty and 10 were killed.