The suspect is also dead, Isaac said.
Cincinnati Police confirmed they were investigating an "active shooter/officer involved incident" at the 30-story building on Walnut Street, which houses the bank and several other companies, around 9:30 a.m.
Cincinnati Police say he lived in an apartment on Miami Avenue in North Bend. Cincinnati.com reported that the scene is now secure but that there are multiple victims.
Witness Leonard Cain, who said he heard up to 15 gunshots, was walking into the bank when someone alerted him of the shooting.
"We send our prayers to the victims and their families", said Cincinnati Mayor John Cranley. "And I'm thinking about how I can make a difference in the future", Whitney Austin said in a statement obtained by Louisville CBS affiliate WLKY.
"Horrific, grotesque and unacceptable", he said.
The building is home to Fifth Third Bancorp's headquarters along with a number of other businesses, including ice cream, pastry and sandwich shops.
Michael Richardson told Cincinnati.com that he saw the man shooting in the lobby, saying, "I looked behind me and saw the guy - he shot and then he shot again". Then, she heard more that "sounded as if they were getting closer and closer". "Square and surrounding area will be closed to foot traffic".
The victims have not been identified. Five others were taken to a Cincinnati hospital for treatment.
"Oh, no, no, no, no", the woman said as she slumped against the wall and spoke to Santa Perez's sister, the paper reported. "After that I started running". Initially, police had thought Santa Perez had entered at the loading dock and began shooting there, but Isaac said Friday that was because some of the shooting victims had ran to that area.
He was born in Pureto Rico and had been living in the city since at least 2015, Isaac said.
A witness said a woman walked into the bank wearing headphones, and she did not hear warnings not to enter. "I will be eating lunch on Fountain Square tomorrow, mindful of the true character of Cincinnati".
"I commend law enforcement, fire and EMS personnel who swiftly responded to the scene and share my deepest sympathies with the victims", he wrote.
"Then we knew what was going on", Hanson said.
"We as a country have to deal with it", Cranley said.