The Federal Railroad Administration said it could take months to investigate the cause of a Norfolk-Southern Corp. (NS) crude-by-rail incident on Thursday morning after 21 of 120 cars derailed near Vandergrift, PA (see Shale Daily, Feb. 13). NS said at least 3,500 gallons of crude oil spilled from a tanker car. No injuries were reported, but 35 people were evacuated from MSI Corp., a specialty metals firm that was hit by one of the cars. NS, which is conducting an internal investigation, said the spill was contained to a parking lot and didn't enter storm drains or nearby waterways.