The National Transportation Safety Board is recommending an audit of the Baltimore City Public Schools’ transportation department after the fatal bus crash that killed six people last year. (Jeffrey F. Bill/The Baltimore Sun via Associated Press)

Baltimore City Public Schools failed to review the qualifications of its bus drivers and monitor their criminal driving records, which put students and the public at risk, according to an investigation by a federal oversight agency.

The National Transportation Safety Board issued a report Tuesday calling on state officials to audit the school system’s transportation department five months after a school bus crash killed six and injured 10.

The report found that the man driving the school bus that collided with a city commuter bus Nov. 1 had been involved in at least 12 crashes or incidents while operating a bus or personal vehicle. But because the school system did not maintain files on the driver’s criminal history or kept incomplete records, it could not effectively determine whether the driver should be disqualified from operating a school bus, the report said.

“During its investigation, the NTSB documented numerous instances in which BCPS did not review or maintain records as required to comply with state or federal regulations,” according to the report. “BCPS did not review crash reports, did not maintain crash cost documentation, did not maintain criminal background reports, and had a drug-testing program that did not comply with the Federal Motor Carrier Safety Regulations.”

School bus driver Glenn Chappell, 67, died in the morning crash. In at least two of five school bus crashes Chappell was involved in between 2011 and 2015, he had passed out and injured a teacher’s aide on board, investigators found. Chappell had a history of hypertension, diabetes and seizures that caused him to black out, according to the federal findings.

After one 2011 crash in which Chappell passed out, the school system’s transportation supervisor failed to have a conference with him as required by state law, the report said.

“The NTSB concludes that BCPS did not adequately document or review the school bus driver’s prior crashes or take appropriate action in response to the October 14, 2011, crash in which the driver passed out while driving a school bus,” the report said.

The school system also didn’t appear to track Chappell’s driving record in personnel files, even though the contractor that employed him sent 11 alerts involving criminal charges against him between 2011 and 2014, the report said.

A school bus contractor in a neighboring Maryland school system had previously rejected Chappell for a position because of his criminal record and traffic violations, the report said. In addition to auditing the school system’s transportation department, the agency suggested the Maryland State Department of Education work to clarify policies on when a driver should be disqualified for a position and develop a database that would alert other school systems of people who have been found unqualified to drive a school bus.

In response to the NTSB report, the school system said in a statement that it has already changed several safety protocols, including establishing “systematic and ongoing auditing of driver certification status, increased review of drivers following accidents regardless of cause or fault, enhanced programs for driver retraining and in-vehicle monitoring.”

The school system also said it has implemented protocols to improve communications between the district and bus companies it has under contract to provide service.

“The report received today from the National Transportation Safety Board will contribute to continuous improvement of our transportation services,” the statement said.

The transportation board acknowledged the school system’s changes but urged it to go further:

“Although BCPS has taken some steps to improve its processes, the risks posed by unqualified drivers remain.”