There's been an arrest in a deadly school bus crash in Chattanooga, Tennessee.

FOX's Tonya J. Powers has more:

Investigators say the bus hit a utility pole before it flipped over and wrapped around a tree. They're looking at speed as a factor, but want the black box from the bus, and to review the video evidence.

Interim Hamilton County school superintendent Dr. Kirk Kelly says five children were killed:

(Kelly) "Of those deaths, three were in the fourth grade, one was a kindergartener, and one was a first grader."

It took two hours for emergency workers to get all the kids off the bus.

Kelly has been consoling the parents:

(Kelly) "It's the toughest thing that you will ever do in your life."

Johnthony Walker now faces charges, including five counts of vehicular homicide and more could follow.

Police say there's no obvious roadway conditions that led to the crash, and they're looking to see if alcohol may have played a role.

Tonya J. Powers, FOX News.

Follow Tonya J. Powers on Twitter: @TonyaJPowers