The driver of a Chattanooga school bus allegedly responsible for an accident that killed six children entered a plea of not guilty this morning during his arraignment. The charges comes from Hamilton County grand jury indictments.

Johnthony Walker issued the plea in response to six counts of vehicular homicide, four counts of reckless aggravated assault, one count of reckless endangerment, one count reckless driving, and one count of use of a portable device by a bus driver.

Investigators say the 26-year-old was driving a bus for Woodmore Elementary in November when he lost control of the bus and crashed into a tree. Investigators with the NTSB say Walker was driving over the speed limit before the crash. The route Walker was using at the time on Talley Road was also not an approved route