CHATTANOOGA - A Tennessee school bus driver has pleaded not guilty to six counts of vehicular manslaughter in a crash last November that killed six children.

WTVC-TV reports that Johnthony Walker was arraigned via video Friday morning in Hamilton County Criminal Court.

Walker is also charged with four counts of reckless aggravated assault, one count of reckless endangerment, one count of reckless driving and one count of use of a portable electronic device by a school bus driver.

Authorities have said Walker was speeding Nov. 21 when the bus swerved into a tree with 37 elementary school students aboard, killing six children and injuring several more.

His next court date was set for April 19.