WASHINGTON, D.C. — Accidental acceleration may have been a factor in the 2005 school bus accident in Liberty, Mo., in which two people were killed, the National Transportation Safety Board (NTSB) said.

The bus driver in that accident lost control of her bus and hit two vehicles, killing two motorists and injuring at least 23 students. The driver reportedly told officials that she could not stop the bus.

The NTSB arrived on the scene and launched an investigation. The agency announced this week that information uncovered suggested that “pedal misapplication” — accidentally hitting the accelerator instead of the brakes — was a factor in the crash.

The NTSB subsequently investigated four accidents involving heavy vehicles, dating from 2005 to 2008, in which pedal misapplication was determined to be a factor.

At a public meeting on Tuesday, the agency will unveil a report examining pedal misapplication through the analyses of those five accidents, as well as information gathered from previous work on unintended-acceleration incidents.

The report evaluates the benefits of brake transmission shift interlock devices, pedal design, positive separation and event data recorders to determine if they are effective in preventing accidents and whether further preventive measures or actions are needed. The meeting, which will also cover recommendations on helicopter emergency medical services, is scheduled for 9:30 a.m. EST on Tuesday, Sept. 1, in the NTSB board room and conference center. A live and archived Webcast of the proceedings will be available at www.ntsb.gov/Events/Boardmeeting.htm.