Sorry but I don't have any specific burial information on Private Roberts. My records do indicate that he was killed in the collision and was not one of the men listed as having died from injuries.
Regardless of what some have said(without contemporary reports to prove), those that died at the collision site were sent up the line to their home stations along the NO&GN RR, not along the tracks or down in the swamp.
Those that died later were either buried in New Orleans or were retrieved by their families for burial at their homes.
"Lest We Forget-The Immortal Seventh Mississippi"