Acting ICE Director Todd Lyons described the Wednesday morning shooting at a Dallas Immigration and Customs Enforcement facility, which resulted in the death of one detainee and left two others critically injured, as his “worst nightmare.”

For Lyons, who previously worked in a Dallas ICE office, the shooting “really hit home.”

“Seeing the photos today, some of the bullets were in an office that I once occupied there,” he remarked on “Top Story with Tom Llamas.” “It’s just a terrible feeling. People often ask me what keeps me awake at night. It’s the safety of the men and women of ICE.”

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Gunfire erupted around 6:40 a.m. on Wednesday, injuring three detainees. One died at the scene, while the other two were transported to the hospital with gunshot injuries, according to Dallas police. No ICE officers were harmed.

“My heart goes out that detainee’s family. We’re charged with their protection, their custody. Nothing like that should happen,” Lyons said.

The shooter, identified as Joshua Jahn by multiple senior law enforcement officials acquainted with the investigation, fired from a nearby roof or elevated position into the field office’s sally port, ICE reported.

ICE stated that the shooter was found dead from a self-inflicted gunshot wound. The Dallas FBI office noted that a bullet discovered near the shooter contained messages with “anti-ICE” sentiments, labeling the incident as an act of “targeted violence.”

Lyons mentioned he was informed the shooter fired “indiscriminately,” hitting windows and lobby doors, and that the attack was directed at the sally port, where detainees are brought in. The victims were in vehicles when they were shot, he explained.

“The detainees weren’t outside a vehicle. The shooter was just shooting at random vehicles inside. They were still hit inside the vehicle,” Lyons said. “There were some brave men and women on the ground that went into those vans, were pulling those detainees out while they’re under fire.”

He said the shooting was particularly alarming because it happened in the morning commute hours, near an interstate, apartments and businesses, meaning more people could have been hurt.

“This was a targeted attack on ICE, but this really could’ve hurt anyone,” Lyons said.

Lyons said there has been an increase in attacks “on ICE officers and agents nationwide.”

“It’s bad enough the men and women of ICE have to go out there and put themselves in harm’s way, doing their law enforcement mission, but never thinking that in our own facility, our own location, we take sniper fire in a major city,” he said.

His message to ICE agents is: “I totally have their back.”

“My No. 1 mission is making sure they go home to their families every night,” he said.