HURRICANE, W.Va. (AP) — Nine students were injured Wednesday morning when a West Virginia school bus hit a tree, officials said.

One student was in serious condition and will need surgery due to internal injuries, but the other injuries appeared to be minor, Putnam County Sheriff Bobby Eggleton told news outlets.

It appears the bus driver experienced a medical emergency that led to the crash, Eggleton said. The driver also was taken to the hospital, but an updated condition wasn't available.

There were more than two dozen students on board the bus when the crash occurred, with most attending George Washington Elementary and Middle schools, officials said.

The school district said in a statement that it was grateful for the quick and overwhelming response to the crash.

“Putnam County Schools extends our sincere thoughts and prayers to our PCS bus operator and all students involved,” the school district said.