Victoria Buczynski of Miami said she saw the collapse while she was working at Gurkha Cigars across the street from the construction site.
"It fell to the ground like a house of cards," Buczynski said. "The construction workers started running out, screaming. It was loud. Our entire building shook."
William P. Byrne, president and chief executive officer of the garage contractor, Ajax Building Corp., said an internal review was being launched to determine the cause. Byrne said the company would embrace "any additional protocols, policies and procedures that will enhance and ensure the continued priority of safety."
Ground was broken on the $22.5 million project in February, and the 1,855-space garage was to be finished in December, according to Ajax's website. The first floor was to have classroom and office space. The structure is next to the college's main office building and nestled among other campus buildings.
The college serves about 8,000 students and is one of several campuses in the Miami Dade College system. The campus opened in 2006.