It's a scene that would make any parent shudder -- a 4-year-old girl tumbles out of the back of a moving bus in the middle of a busy highway.

Video of the incident shows the back door of the bus springing open and the young girl plummeting to the road. "I couldn't believe it, it was so shocking," said Ryan Ciampoli, who was driving behind the bus in Harrison, Arkansas.

Ciampoli, who is a trained emergency medical technician, ran to the little girl's rescue after her terrifying tumble on Wednesday. His vehicle is fitted with a dash cam that recorded the incident because he sometimes uses it when on duty, Ciampoli said.

At first the girl was unconscious, but he cradled her and talked to her until she came round.

"For a very brief time she had got enough consciousness to say 'where is my mommy?,'" he said.

He picked her off the hot pavement and moved her off the busy road while waiting on emergency medical services. "Obviously you want to leave her laying there, if she's not in danger, but we're in the middle of a state highway," he told CNN affiliate KHBS-TV. "So I couldn't leave her just laying there."

The little girl is recovering at the hospital. She suffered a broken jaw and will undergo surgery.

It is unclear if she opened the door or if it wasn't locked. CNN has reached out to police for comment but they weren't immediately available Sunday.