A Tucker Middle School student was in critical but stable condition after an armored truck struck her as she tried to board a DeKalb County school bus Wednesday morning.

Authorities did not describe the injuries suffered by the 13-year-old girl, who was not identified. She was taken to an undisclosed hospital, and “the next few days are very important,” said police spokesman Marcus Hodge.

Hodge said the bus had stopped on Hugh Howell Road shortly before 8 a.m. with its red “stop” lights flashing. He said armored truck driver Brian Gaines, 49, of Snellville, tried to stop, but the truck slid into the bus and hit the girl.

Possible charges against Gaines had not been decided Wednesday afternoon. Traffic experts will reconstruct the scene to determine his speed, Hodge said.

The bus driver, Sterrie Eccles, had a knee injury but declined to be taken to a hospital, Hodge said.

—Staff writer David Simpson contributed to this report.