BANFF, Alta. -- The Transportation Safety Board says a fractured piece of railway track caused a derailment last year that sent coal ash waste into a creek in Banff National Park.
A report has concluded that a loose joint and minor cracks in the track had worsened over time with train traffic.
Regular inspections did not identify the deteriorating condition of the rail.
The derailment of the Canadian Pacific Railway train on Boxing Day destroyed a bridge and sent 15 cars off the tracks.
A hazardous coal combustion by-product called fly ash, as well as soybeans, spilled into the water.
The agency says crews worked in the spring to clean up the ash but environmental monitoring is to continue for three to five years, possibly with more remediation.
