Three people were at hospitals in critical condition. The other 27 surviving passengers were hurt, but their injuries were less extensive, authorities said.
Eight of the 14 patients initially taken to Ryder Trauma Center at Jackson Memorial Hospital were in stable condition while two others were in critical, said hospital spokeswoman Lidia Amoretti. Local reports said three people with lesser injuries were later released.
A majority of the injuries were facial due to the frontal impact, said Miami-Dade Police spokesman Det. Alvaro Zabaleta.
He said the driver was not familiar with the airport area and it was too early to say if charges would be filed. Investigators said they had conducted interviews Saturday with the driver, who suffered minor injuries.
"The preliminary info tells us that he wasn't too familiar with the area surrounding the airport, and that's what led him to take perhaps the wrong ramp that led him onto the property of the airport, and because of not being familiar with the airport, did not know or really see the height requirement in order for that bus to clear the overpass," Zabaleta said.
The bus was privately owned and typically used for tours, authorities said.
Markings on the bus show it was owned by Miami Bus Service Corp.
The company owns three motor coaches, according to the records. Miami Bus Service Corp. officials did not immediately respond to a phone message Saturday.
Federal Motor Carrier Safety Administration records found online show the company has had no violations for unsafe driving or controlled substances and alcohol. It also had not reported any crashes in the two years before Oct. 26, 2012.
The records show it did receive three citations related to driver fatigue in April 2011.
Associated Press reporter Jackie Quinn in Washington contributed to this report.