TEMPE, AZ — The National Transportation Safety Board has released its preliminary report regarding the train derailment near Tempe Town Lake in late July.
Officials say Union Pacific estimates the incident, which led to the partial demolition of the railroad bridge that crosses Tempe Town Lake, caused $8 to $10 million in damage.
"The Federal Bureau of Investigation (FBI) conducted an initial investigation to uncover any evidence of criminal activity; however, none was found," the preliminary report reads.
The train, which had three locomotives and 97 mixed-freight cars that measured nearly 7,000 feet in length was traveling 23 miles per hour at the time of the derailment, the report says.
"All aspects of the Tempe, Arizona, accident remain under investigation as the NTSB determines the probable cause, with the intent of issuing safety recommendations to prevent similar accidents," the report says.
Maintenance records are still under review.
Read the full preliminary NTSB report here.