By Jeremy Ross

CHICAGO (CBS) — Robbers targeted an armored truck filled with cash in Chicago.

The guard on that truck opened fire, shooting one of his attackers. It all happened outside a North Austin bank.

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CBS 2’s Jeremy Ross reports while drivers are using the ATM outside, for hours the bank has been closed down, because of the violence that happened and the investigation that followed.

“There were like 20 police officers all the way around going crazy.”

It’s not the first time Isaac Lopez listened to the sounds of gun violence.

“I heard the gunshots. It was like an automatic something,” Lopez said. “That’s what got me by surprise. So early in the morning.”

Police tape and squad cars made their way to a BMO Harris bank at Lamon and North Avenue following the gunfire. Police said there, a security guard  with a Garda armored truck was emptying an ATM when a dark colored SUV with two people inside pulled up.

At least one had a gun and demanded cash.

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Investigators believe the security guard fired hitting one of the robbers. Both drove off, leaving a crime scene and a lasting impression.

“In plain words it’s stupid. Because how you rob an armored in an open space. Or maybe they were desperate,” Lopez said.

GardaWorld, the company overseeing the trucks, confirmed one of its armored vehicles was the target of a failed robbery attempt, adding its employees are safe and were unharmed in the crime.

The company called the actions of the employees brave and vigilant, and thanking Chicago police for their quick response.

“I feel safe that the CPD, at last, they’re taking care of us,” said Lopez.

“I’m supposed to go to the bank to take care of some stuff, but no I’ll have to leave it to Monday because the bank is closed right now,” said Lopez.

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There is no update from police if anyone is in custody in connection with the crime. GardaWorld added it is cooperating with law enforcement in the investigation.