Police say the seven children killed in a three-vehicle crash near Lake Butler had been adopted by the same family.
All were in a car rammed by a truck into a school bus. A 15-year-old girl was driving illegally. It's unclear why there was no adult with them.
The teen driver was the oldest of those killed. The youngest was just 21 months.
Police say the truck hit the car from behind and pushed it into a school bus, causing the car to burst into flames. Investigators say evidence from the scene shows the truck didn't brake before hitting the car. The bus ended up 200 feet from where the car struck it.
Nine students were on the bus and three were thrown from the vehicle by the force of the crash. State police said three were seriously hurt and six others suffered minor injuries. Hospital officials say they received five children, two of whom were in fair condition and three in serious condition.