Police said a gunman entered the building through a loading dock and made his way to the lobby of the office building. It's unclear if the gunman shot himself or was shot by officers, police said. The hospital later said on Twitter that two of the four victims had died, another was in critical condition and the fourth was in serious condition.
"This is abnormal. No other industrialized country has this level of active multiple shootings on a regular basis", Mayor John Cranley said about the shooting.
Afterward, police swarmed the gunman's apartment in North Bend, Ohio, about 15 miles west of Cincinnati. The officer gave the phone to his wife and they talked as she waited for an ambulance to arrive. As previously announced, two other victims received at UC Medical Center are deceased.
Richard Newcomer, a contractor who worked for Gilbane Building Company, was one of three killed. Neighbor Karen Rose said Perez's auto recently broke down, leading him to take the bus; she said he seemed "standoffish" and often had ear buds in. He died at the scene, Isaac said.
Police did not say much about Perez.
Santa Perez is a US citizen born in San Juan, Puerto Rico, family members said.
"I heard about eight gunshots, and I actually got on my knees".
Isaac said the rampage took place on the loading dock and then the lobby of the Fifth Third Center in the heart of downtown. "And I'm thinking about how I can make a difference in the future", Austin said.
Investigators have not identified a motive for the shootings, Issac said. Police believe the firearm was legally purchased, he said.
Another onlooker, Leonard Cain, told a newspaper he had been about to enter the bank when someone warned him about the shooting.
Two people have reportedly been killed and another four people are critically injured.
Cincinnati-based regional banker Fifth Third Bancorp offers thoughts and prayers for "everyone caught up in this bad event".
"Our thoughts and prayers go to the families of the victims, our heartful gratitude goes to the first responders and our continued support goes to this community that we love".
Luis Calderon left his family in Miami a year ago to take a better, executive job with the bank, but he was trying to figure out how to get back to Florida, his wife said.
'She walked in the door and he shot her, ' the witness told Cincinnati newspaper The Enquirer.