Austin, a senior product manager for digital lending for Fifth Third, said two police officers rushed over and got her out of danger, saving her life. No officers were injured.
The suspect was shot multiple times as four police officers approached.
Police said he went into a sandwich shop and other businesses before entering the lobby and opening fire in the building that sits alongside Fountain Square, often a site of concerts, dancing, food trucks and other events around lunchtime or in the evenings.
He praised "the heroism" of police who ended the threat within seconds and the response of other emergency personnel. Isaac said the gun was purchased legally. More details will be released Friday.
Neighbours who lived in a Cincinnati-area apartment building that Santa Perez moved into this year gave conflicting descriptions of him.
"Let's join efforts to help Ana Maria through these hard times, when she has so many unforeseen expenses to cover", they wrote.
Fountain Square is a heavily trafficked landmark in the middle of the city. It is home to retail stores, business offices, hotels and eateries.
Authorities were trying to determine what may have motivated the gunman to carry out the rampage but have said he acted alone. Pruthvi went to the U.S. six years ago.
The two others who died were Luis Felipe Calderon (48) and Richard Newcomer (64).
"We prepare for situations like these and hope they never happen", said Amanda Nageleisen, UC Health spokeswoman.
She then saw people running into the square outside the building and ducking for cover as officers started shooting into the bank.
Newcomer was a superintendent at Gilbane Building Company and working Thursday at the Fifth Third Center, Gilbane spokesman Wes Cotter said. SWAT teams are continuing to sweep the area to ensure safety and to search for possible additional victims. The bank added that it was cooperating with law enforcement and is "grateful for the support and concerns from our neighbors throughout Cincinnati and the country".
Cranley, the mayor, became emotional as he described watching the full, unedited video, saying that he saw a receptionist "who literally was in the middle of gunfire", and the look of fear on her face and relief after the shooting was over and police arrived.
Ohio Governor John Kasich has ordered flags in Ohio to be lowered to half-staff until Monday.