The driver was killed, said Capt. John Malone, who commands state troopers in the Mobile district.
The bus was carrying Texas high school students returning from a trip to Walt Disney World in Orlando. All the passengers had been accounted for on Tuesday morning.
The bus plummeted into the 50-foot ravine around 6 a.m. CT and authorities believe about 45 people were on the charter bus bound for Houston. The Baldwin County Sheriff's office said it was not immediately clear what caused the bus to veer onto the Interstate 10 median, which ends at a steep embankment where the highway passes over Cowpen Creek.
Sacred Heart Hospital in Pensacola received 18 of the patients, according to its website.
Five remain hospitalized and all are in serious condition. He said at least one person had to be cut out of the wreckage.
Davidson said the community has rallied together to assist crash victims in any way they can.
"Everybody is being transferred to a hospital to at least be checked out", Elliott said.
A video of the crash shot in the early morning showed a bus on its side in a grassy aqueduct or ravine as rescuers with flashlights scoured the area.
The interstate is expected to remain closed most of the day.
Many people were injured in the Tuesday morning crash near the Alabama-Florida line on Interstate 10. That number is 251-972-6807.
The students are from Channelview High School, said Mark Kramer, spokesman for the Channelview Independent School District.
Sources say the bus was carrying students back home to Channelview, Texas, which is in the Houston area. The other bus continued on to Texas. Investigators with the National Transportation Safety Board are headed to the crash site.
We pledge our assistance in cooperating with local authorities in the investigation.
"Cecilia and I are heartbroken by the news of this tragic accident, and we offer our prayers to all these young Texans and their families", Abbott wrote.
Lowery said uninjured passengers will be reunited with family members and Channelview school officials at Coastal Church on County Road 64 in Daphne, Alabama.