Two freight trains collided and partially derailed Sunday and Yazoo County authorities said they had recovered the body of one crew member and were searching the wreckage for three others.
Yazoo County coroner Ricky Shivers says one body has been recovered and others are missing.
Shivers says a fire that followed the crash had hampered search team efforts.
The Mississippi Emergency Management Agency had said earlier that emergency officials reported all four crew members had been confirmed dead. Shivers says no other injuries were reported.
The collision northeast of Bentonia in west-central Mississippi involved two Canadian National Railroad freight trains.
Spokeswoman Karen Phillips says representatives of the National Transportation Safety Board and the Federal Railroad Agency were headed to the site.
Phillips says the cause is still under investigation, but she downplayed the fact that the trains were on the same set of tracks, saying it is a common practice in the rail industry.
One of the cars leaked vegetable oil and caught fire, but the flames were extinguished.
Phillips says the northbound train had 137 cars and two locomotives, and the southbound train had 107 cars and four locomotives, Phillips said.
About 45 to 50 people were evacuated from homes in the area near Little Yazoo.