The suicide bomb attack at the Abbey Gate of Hamid Karzai International Airport in Afghanistan that killed 13 U.S. servicemembers and injured at least 170 civilians was conducted by a single attacker and was not followed up by enemy gunfire, the Pentagon said Friday.

U.S. military leadership briefed the media briefing on its investigation into the ISIS-K bombing, which was the deadliest day for U.S. troops in 10 years. The bombing occurred as the U.S. conducted its military withdrawal and civilian evacuation from the country.

AFGHANISTAN WITHDRAWAL ‘DEBACLE’: WHY HAS NO ONE BEEN HELD ACCOUNTABLE?

The key findings of the investigations indicate that the bombing did not amount to a complex attack that did not kill any U.S. or civilians post-blast. Only one explosion occurred, and anyone caught in the blast could not be saved.

Injured people arrive at a hospital in Kabul, Afghanistan, Aug. 26, 2021.

Injured people arrive at a hospital in Kabul, Afghanistan, Aug. 26, 2021.  (ASVAKA NEWS/via REUTERS)

Investigators found no gunshot wounds among those injured. The ball bearings in the explosive, along with the gunshots fired at the time as "warning shots," led to the belief that some had been shot during the explosion. 

Crowds around the gate were "large and unruly." The blast radius extended to around 330 feet. 

CLICK HERE TO GET THE FOX NEWS APP

The investigators stressed that "every service member that could be was saved." 

This is a developing story. Check back for updates.