(The Center Square) – Former U.S. Secret Service agents and security experts argue the Secret Service’s failure to prevent an assassination attempt against former President Donald Trump on Saturday was “apocalyptic,” exhibiting a “massive security breach.”

U.S. House Speaker Mike Johnson, R-Louisiana, has called for a congressional investigation. Multiple members of Congress are asking how a shooter ever reached a rooftop of a building to fire a shot at Trump, including U.S. Rep. Cory Mills, R-Florida, an Army veteran and counter sniper for the State Department who coordinated protective details for then Vice President Joe Biden, Condoleezza Rice and First Lady Laura Bush.

The assassination attempt on Trump was “a massive security breach,” Mills told CNN. The distance between the shooter and Trump was roughly 400 to 500 feet, “which is nothing for a shot adjacent to the stage of the president,” he said. “There was no one on that building, … in the building, standing next to the building to ensure there’s no access to the building,” he said. If there were, they “could have prevented this shooting.”

In an interview with Fox News, Mills said that the shots fired were the kind that soldiers learn in basic training boot camp and are “requested to make within nine weeks. This is one of the easiest shots.”

He said his job at the State Department involved working with an advanced team to establish a perimeter and “identify areas of threat that you would be able to mitigate … whether it be a building, … a lone tree … a parking lot. … Bottom line is this is massive negligence.”

Secret Service spokesperson Anthony Guglielmi has said agents responded quickly and the agency “added protective resources and technology and capabilities as part of [Trump’s] increased campaign travel.”

Former Secret Service agent Dan Bongino questioned this claim, asking on Fox News, “Which ones? You’re telling me the best technology you have was deployed and you missed a shooter 130 yards away … and even worse, it’s broad daylight on a white roof.”

He asked if there was forward-looking infrared deployed and if there was aerial support like drones and helicopters.

Bongino also pointed out that Trump “knew to duck … and saved his own life. That’s just a fact. The evacuation did not go right. The rule with the Secret Service is ‘cover the protectee’ and evacuate. The other rule is ‘maximum to the protectee, minimum to the problem. … Because you don’t know that’s the only problem. It could be a distraction. There could be another person in the crowd … you could be looking at multiple shooters.”

“The failure here is absolutely catastrophic,” he said, calling on Secret Service Director Kim Cheatle to resign immediately. He said Secret Service “absolutely resolutely 100% failed. This was an apocalyptic security failure. … An uneventful failure is never a success. The fact that Donald Trump didn’t die … is no reason for anybody to take some kind of victory lap.”

Former Secret Service agent Jeff James agreed, telling WTAE ABC News the agents on the stage should have moved Trump off sooner because the first shots fired “may have been the precursor in the real attack. There may have been four more gunmen who were going to start opening fire. I would have rather seen him get him into the armored cars and get him out of there more quickly.”

Bill Pickle, a former deputy assistant Secret Service director, told the Wall Street Journal, “The reality is there’s just no excuse for the Secret Service to be unable to provide sufficient resources to cover an open rooftop 100 yards away from the site. And there’s no way he should’ve got those shots off.”

Retired Secret Service agent Donald Mihalek called the failed assassination attempt “historic, drawing parallels to the 1912 shooting of Theodore Roosevelt in Milwaukee,” the Journal reported. “Roosevelt, then a former president who was running for a third term in the White House, was shot while heading to a campaign event. He survived the attempt on his life.”

Erik Prince, who previously provided diplomatic security services, said, “unaccountable bloated bureaucracies continue to fail us as Americans. Donald J. Trump is alive today solely due to a bad wind estimate by an evil would be assassin.”

Prince analyzed the wind at the time of the shot, arguing it was enough to displace the bullet two inches from Trump’s “intended forehead to his ear. DJT [Trump] was not saved by USSS [U.S. Secret Service] brilliance. The fact that USSS allowed a rifle armed shooter within 150 yards to a preplanned event is either malice or massive incompetence.

“Clearly there was adequate uncontrolled dead space for a shooter to move into position and take multiple aimed shots,” he said, adding that one counter sniper “was clearly overwhelmed as his face came off his rifle instead of doing his job to kill the shooter.”

A counter sniper killed the alleged shooter after he shot several rounds, wounding Trump, killing one, and critically wounding two others.

“In my old business of providing Diplomatic Security in two active war zones we were expected to execute the basics, or we would be fired,” Prince said. “Clearly USSS failed at the basics of a secure perimeter and once shots were fired, their extraction was clumsy and left DJT highly exposed to follow on attacks.”

He also expressed no confidence in anyone being held accountable, saying, “That’s not the Washington way. Unserious and unworthy people in positions of authority got us to this near disaster.”