At 2:00 p.m. on May 20, 2014, Employee #1 was in a tank railcar confined space containing residual sweet crude oil without prior entry assessment and without wearing a harness with stand-by extraction equipment. While Employee #1 was shoveling crude oil inside a permit-required confined space tank railcar. Employee #1 was wearing a full-face supplied-air respirator (SAR), MSA Type-C Ultraview, attached to shop air and filter pot with no carbon monoxide filtration.