ATLANTA — The 10-line report, written on wide-ruled notebook paper by an elementary school student in Chattanooga, Tenn., arrived on Nov. 16.

“The bus driver drives fast,” the Woodmore Elementary School student wrote. The driver of Bus No. 366, the child added, drove so that it felt “like the bus is going to flip over.” And when a student stood in the aisle, the child wrote, the driver “stops the bus and he makes people hit their head.”

Five days later, the bus driver, Johnthony K. Walker, driving 37 children home from Woodmore, strayed from his route and crashed, leaving six children dead in one of the country’s deadliest school bus wrecks in recent years.

The crash, for which Mr. Walker has been charged with vehicular homicide, is being investigated by the National Transportation Safety Board and the Chattanooga police. Records released Friday night by the Hamilton County Department of Education showed that Mr. Walker’s behavior was a frequent worry this semester.