It happened just south of Sylvarena at a construction site for a major pipeline.
Smith County emergency responders were called around 3:30 Wednesday afternoon to the site where several crews were working on a pipeline that was lying above ground.
Minutes before something went terribly wrong, and in an instant one man was killed and twisted metal was scattered across the field.
The pipeline exploded on County Road 99.
Smith county investigators tell us one man died at the scene while three others were seriously injured.
They were airlifted to University Medical Center.
More than a dozen workers were reportedly testing a newly installed pipeline with nitrogen when the explosion occurred.
"One man looked to be burned and the other two just had some injuries because I know the pipe itself had fallon on one of the men. I'm not sure of the companies name. There's at least two or three companies involved in this, and I'm not at liberty to say right now," said Smith County Sheriff Charlie Crumpton.
Some men at the scene wore helmets with Kender Morgan as the company logo.
Other trucks were labeled Boardwalk Pipeline Partners and Southern Natural Gas.
The names of the victims have not been released.
Investigators said the one ton cover to a hole blew off and has not been located.
Nikki McNeer lives on the same road and was awakened by the noise.
"I was laying in bed taking a nap because I had just got off from work and a few hours ago. I just heard it sounded about two or three miles up the road. I just kinda heard what sounded like a firecracker outside my window and I woke up and went up front and I told him I said 'I think somethingexploded' you know," said McNeer.
No evacuations were ordered.
Officials said all of the victims were from out of state, including Louisiana.
The Mississippi Emergency Management Agency, investigators with the Mississippi Public Service Commission, the Smith County Emergency Management Agency,as well as the Sylvarena Volunteer Fire Department and others responded.