Freight train derailments, including the recent one in East Palestine, Ohio, have prompted officials to examine what is causing the accidents and whether they are happening more frequently, says The Wall Street Journal, which has analyzed more than 20 years of federal data on accidents.

Derailments rank as the most common type of accident involving the major freight railroads, and federal data shows equipment failures are increasingly responsible for derailments. Federal data shows the number of derailments among major freight railroads has fallen sharply since 2000 but that the rate of derailments for some railroads has increased in more recent years.

The increases have come even as the railroads haul more freight over fewer train miles. Despite fewer miles being traveled, the rate of derailments has increased in five of the last seven years. 

The derailment rate among the seven Class I railroads is also higher than it was a decade ago.