A security guard was shot and killed when he was ambushed as he stood guard outside of a bank during an attempted bank robbery.

The incident occurred at approximately 1 p.m. at the First Midwest Bank on Ridge Road in Gary, Indiana, when two suspects were seen on bank surveillance cameras carrying guns before ambushing 55-year-old retired Cook County Sheriff’s Deputy Richard Castellana as he was on patrol outside the establishment, according to ABC’s Chicago station WLS-TV.

Witnesses who were nearby told WLS that they heard at least two gunshots during the attack.

“I didn’t see him fall down but when we looked over there with the police you could see man laying on the front of the door,” James Ripkowski, who works across the street from the bank, told WLS in an interview after the incident.

“I actually heard the shots but we actually thought it was like regular fireworks,” Randy Martin, another witness to the shooting, told WLS. “”For them to have the guts and the audacity to do something like that, that is beyond me.”

Castellana of Tinley Park, Indiana, who served as a Cook County Sheriff’s Deputy for 35 years before retiring in 2019 and taking a job as a security guard at the bank, died of injuries suffered at the scene of the crime.

Heavily armed federal, state and local authorities responded to the shooting and immediately began a manhunt for the two suspects involved in the shooting, according to WLS.

One suspect was caught a short time later hiding behind some trees in a wooded area close to the bank. Authorities focused on the same area in an attempt to find the second suspect but have so far been unable to locate him.

Many who work in the area said they saw Castellana patrolling the parking lot on a daily basis and described him as an incredibly kind and approachable person.

“He was human just like us, you know,” said fellow security guard, Melissa Mali. “We talked about family things. We talked about everything outside of just ‘hey, I work at a bank.’ That was my buddy. I didn’t look at him as a security guard at a bank. That was my friend.”

The Cook County Sheriff’s Office released a statement sending condolences to the family of the 55-year-old police force veteran.

“We are saddened to hear about the tragic passing of our former Deputy Sheriff, Richard Castellana. Deputy Castellana served Cook County for 35years until his retirement in 2019. He will be greatly missed by his colleagues and friends. We send our deepest condolences to his family and loved ones,” the statement read.

The first suspect has not yet been publicly identified by authorities and charges have yet to be filed. The Lake County Sheriff’s Department said their investigation is ongoing.

Said witness Mike Richardson to WLS: “Every day we see the security guards walking around over there. It’s just surreal when you see something like that, you just don’t believe it.”