Perry, Okla.-Burlington Northern Santa Fe (BNSF) investigators are still looking for the cause of a 15-car derailment here on the evening of Jan. 13 involving two tanker cars carrying liquid fertilizer. According to BNSF spokesman Joe Faust, traffic on the main line was restored by the next evening, but an advisory went out to customers saying that arrival delays of up to 24 hours should be expected. Reports from the scene indicated that both fertilizer cars lost product in the upset, and that no impact had been detected on the waterways in the area. But Faust said only one of the tankers was punctured and emptied an undetermined amount of the fertilizer. He said soil in the area soaked up the liquid and was being checked by an environmental team that was called in to assess any environmental problems at the site. Indications were that a rail broke as the train was passing over it. Two families living near the wreck were evacuated from their homes to a local motel as a precaution.