The motive of the shooter, whose identity has not been released, was not known.
"She walked in the door and he shot her", Cain told The CincinnatiEnquirer, adding that he heard up to 15 shots fired. "He was actively shooting innocent victims", the mayor added.
Authorities said the death toll in a gunman's attack on a downtown Cincinnati office building could have been higher.
He was not a current or former employee at the center, whose primary tenant is the Fifth Third Bank headquarters, and officials say they are not sure of his connection with any surrounding businesses.
The chief says they had a "quick response" and 'there is no additional threat'.
Austin is grateful for the officers who aided her and for the support from many others, the spokesperson said.
The chaos unfolded alongside Fountain Square, the heavily trafficked park at the city's center.
The victims have been identified as Pruthvi Raj Kandepi, Richard Newcomer and Luis Felipe Calderón, according to the Hamilton County Coroner. Two other victims are being treated at University of Cincinnati hospital.
Ebony Ginyard, who works at a Dunkin' Donuts in Fountain Square, said she and other workers and customers dropped to the floor when the shooting erupted, according to Reuters. "After that, I started running", Richardson said. Isaac said the gunman then entered the bank's lobby where he exchanged gunfire with police.
"This is a horrific incident", Isaac said.
Emergency personnel and police responded to reports of an active shooter situation near Fountain Square, today, in downtown Cincinnati.
Witness Cheryl Eagleson said she was across the street from the bank when she heard "loud pops" from a gun, prompting people to drop to the ground.
"It could have been any one of us", Cranley said.
People are also being asked to continue to avoid the area around Fountain Square.
A police officer at the scene told The Associated Press there are at least two, possibly more, people who have been shot.
A WKRC-TV reporter posted pictures to Twitter showing police responding to the scene. We knew immediately something was wrong.
Witnesses describe a chaotic scene.
For example, the newspaper reports that one victim was found in a local ice cream shop and another was discovered at 5th and Walnut.