GUM BRANCH, Ga. — A school bus driver on her early pickup route lost control on a dirt road and smashed into a tree Tuesday, killing a 5-year-old girl and sending 21 other children to hospitals.

The crash happened on a foggy morning just before 7 a.m. as the bus was gathering Taylors Creek Elementary School students in tiny Gum Branch, a city of fewer than 300 residents that backs onto a large military community about 50 miles southwest of Savannah.

It’s too soon for investigators to know if the 62-year-old driver, who also was hospitalized, will face any charges, said Lieutenant Thornell King of the Georgia State Patrol. King said video from a security camera on the bus showed her struggling with the gear shift right before the crash.

‘‘The driver, she made a right-hand turn and she hit a bump,’’ probably a roadside ditch, King said. ‘‘After she hit the bump, you can clearly see on the video her struggling with the gear shift as if to put the bus in park or trying to slow it down.’’

King said it did not appear on the video that the driver was accelerating at high speed, and he said it was possible that ‘‘something malfunctioned’’ on the bus.

King identified the girl killed in the crash as Cambria Shuman. He said she had been sitting in one of the front-row passenger seats. The bus had no seat belts.

Associated Press

The impact caused the bus roof to cave in on the young passengers, the State Patrol said in a news release. All of the other children on board were taken to nearby hospitals to be treated for ‘‘bumps and scrapes and lacerations,’’ said Mike Hodges, the Liberty County public safety director.

The impact trapped the driver in the crushed front section of the bus. She was taken to a Savannah hospital after being freed by emergency responders. Her condition wasn’t known immediately, but King said she had been conscious and talking with school officials.