It appears that speed was not a factor in a recent train derailment in Lyon County, Iowa.

According to a preliminary report released today by the NTSB, the Burlington Northern Santa Fe train was traveling under the maximum allowable speed when emergency brakes were applied.

Ten tanker cars released about 230,000 gallons of crude oil when 33 cars derailed near Doon, Iowa on June 22.

The report says heavy rain in the 48 hours leading up to the derailment washing out track and flooded the area near the location.  A final report is still pending.