The security guard who was killed when a crazed gunman opened fire in a Soho federal building was mourned by friends and colleagues in lower Manhattan on Thursday.

Slain guard Idrissa Camara was remembered as a hard worker and devoted dad. Some 200 people attended a memorial service for him in a garden near the building where he was gunned down.

“He was crazy about his kids,” fellow security guard Juan Veras said. “He had a daughter, 18 months. He showed me videos from their trip to Dorney Park.”

Another co-worker, Sheila Stanley, called Camara a “beautiful person” and regretted the fact that she could have been there when the gunman, former federal worker Kevin Downing, opened fire.

“That day I left at 4:30 — I forgot my photo ID, I was going to go back,” Stanley said. “It could have been me, it could have been anyone.”

The gunman, Downing, finally went berserk on Aug. 21 — more than 16 years after being canned by the Department of Labor.

He claimed that he was fired when he blew the whistle on “pork-barrel” project.

After killing Camara, Downing turned the weapon on himself and committed suicide.