A gunman stormed into an Old National Bank location in downtown Louisville, Kentucky, killing four and wounding eight, including a police officer hospitalized in critical condition Monday.
At least one other officer suffered a minor injury, and the attacker was also killed, according to police.
City leaders said officers arrived within three minutes and put an end to the carnage.
Police are asking anyone with information on the attack to call their tip line at 502-574-LMPD.
LOUISVILLE POLICE RESPOND TO ACTIVE AGGRESSOR AT DOWNTOWN BANK
8:38 a.m.
Police receive word that a shooter had attacked at the Old National Bank building on East Main Street in Louisville, across the street from a Minor League Baseball stadium.
"We are confirming reports of an active aggressor in the 300 block of East Main," police announced on Twitter. "Please stay out of the area."
Caleb Goodlett, the husband of a bank worker, told the local CBS affiliate that his wife called him from inside the vault, asking him to contact police. When he did, the dispatcher reportedly told him that officers were already on the way.
Another witness in the area, Hagan Curd, took video of the police and ambulance presence outside, and in it multiple shots can be heard as an officer appears to warn drivers stuck in traffic, "Active shooter at the bank!"
By 8:41, police were on scene, authorities said, and the suspect, identified as 23-year-old bank employee Connor Sturgeon, shot at them interim Louisville Police Chief Jacquelyn Gwinn-Villaroel said later.
"We then returned fire and stopped that threat," she said. "The suspect is deceased."
9:30 a.m.
The FBI's Louisville office announces that special agents are assisting local police in connection with the shooting.
10:38 a.m.
"The lone shooter is deceased," police announce on Twitter.
Officers had responded within minutes. It was not immediately clear whether they killed the gunman or he took his own life, according to Deputy Chief Paul Humphrey.
11 a.m.
City leaders deliver updates at a news briefing, saying at least eight had been injured, more than the original six, including a police officer who was hospitalized in critical condition.
"It is clear from the officers' response that they absolutely saved people's lives," Humphrey said. "This was a tragic event."
Gov. Andy Beshear also spoke, revealing that he knew at least two people shot in the attack.
"This is awful," Beshear said at a press conference. "I have a very close friend that didn’t make it today. And I have another close friend who didn’t either. And one who’s at the hospital that I hope is going to make it through."
12:11 p.m.
Mayor Craig Greenberg designates the Kentucky International Convention Center as a place for victims and their families to receive assistance from city officials.
3 p.m.
Police delivered an update to the public, identifying the shooter and the four people who he killed with a rifle during the attack. The deceased victims were all between 40 and 64 years old. Nine other people were hospitalized, police said.
CLICK HERE TO GET THE FOX NEWS APP
This is a developing story. Check back for updates.
Fox News' Haley Chi-Sing and Greg Norman contributed to this report.