The official record of accidents and deaths on the Metrolink commuter rail system is incomplete, marred by inconsistencies and largely hidden from view. The record makes train operations in the Los Angeles region appear to be much less dangerous than they are.

The Times was able to assemble the interactive database and map accompanying this report by drawing on information from several sources, many never before available to the public. To the extent possible, inaccurate or conflicting information was corrected and obvious omissions filled in.

The database suggests that the Federal Railroad Administration's system for tracking hazards is more suited to monitoring cross-country freight haulers than high-speed trains operating in crowded urban corridors.

Only about four of every 10 fatal accidents in Metrolink's records have been reported to the federal agency, which posts the information on its public website.

At least 117 Metrolink system pedestrian deaths and six vehicle deaths do not appear in the federal record.

The federal agency requires train operators to file reports under broad circumstances: an accident at a grade crossing, an accident causing damage to railroad equipment or an accident resulting in loss of life -- except when the death is ruled a suicide.