A lone gunman stormed a bank in downtown Louisville, Kentucky, on Monday morning, killing four people and injuring eight others before dying after a confrontation with police. 

While officials have yet to identify the suspect, they said he was either a former or current employee at the Old National Bank. His connection to the bank, as well as his motive, are still under investigation.

The Louisville Metro Police Department said the suspect entered the bank at 8:30 a.m., before it had opened to the public, and started firing. 

Witnesses said they spotted the gunman with a “a long assault rifle” firing several shots in the first floor of the bank building. 

Rickey Readus, a Louisville resident, told The Post employees ran out to find shelter at nearby businesses. He said one of those employees allegedly knew the gunman. 

Employees inside the bank said they took shelter inside conference rooms and bathrooms as soon as they heard the gunfire.

“The bathrooms on our floor have keycode entry, so it was probably the safest place we could think of to hide,” employee Tammy Madigan told The Daily Beast. “So the six of us went into the men’s room, turned off all the sound on our phones, tried to be as quiet as we could.”

LMPD Deputy Chief Paul Humphrey said police arrived quickly at the scene, clearing the streets and confronting the gunman inside. He said the responding officers exchanged fire with the gunman.

“Ultimately that suspect did die at the scene,” he said. “We are trying to confirm if that suspect did die of a self-inflicted gunshot wound or was killed by officers at this time.”

Madigan said that after the shooter’s death, police ushered the remaining employees out of the building, where some were able to see the gunman’s dead body on the first floor.

It is currently unclear if he took his own life or was shot by police.

University of Louisville Hospital confirmed they received nine patients following the shooting, including two officers and seven civilians.

One of the officers was reported to be in critical condition.

The hospital said at least three patients have been discharged, but did not disclose the condition of the other injured victims.