The parking structure in Doral was under construction at the west Miami-Dade campus.
"It fell to the ground like a house of cards," said Victoria Buczynski of Miami, who works across the street. "The construction workers started running out, screaming. It was loud. Our entire building shook."
One man who died had been trapped for about 13 hours after the collapse. Rescue crews found Samuel Perez after hearing his cries amid the rubble on Thursday and spent hours communicating with him before he was taken to the hospital.
Police identified the other two fatalities as Jose Calderon and Carlos Hurtado de Mendoza. All three of the dead worked for subcontractors of the firm handling the construction of the garage, Ajax Building Corp., said Ajax president and CEO Bill Byrne.
One person is still missing, Miami-Dade police said.
At least seven workers were brought to the hospital with unidentified injuries, while an eighth was treated on the scene and sent home. There were no students in the area because the garage was under construction.
The campus was evacuated and closed for the rest of the week. Investigators planned to pick through the rubble to see what caused the garage to crumble.
The Associated Press contributed to this report.