A rail car filled with extremely hazardous ammonium nitrate did not cause the fiery explosion at a Texas fertilizer plant, investigators said on Tuesday, in their first statement ruling out possible sources of the deadly blast six days ago.
Fourteen people died in the explosion at the West Fertilizer Co last Wednesday, and some 200 were injured.
Investigators said they also ruled out a weather event such as lightning as the cause of the fire and blast, and said they had narrowed down the possible sources to an accident, arson or an unexplained cause.
The repercussions of the blast increased on Tuesday, as the McLennan County district court said at least two lawsuits had been filed against the company's parent, Adair Grain. They were filed by a displaced resident of the town, and insurance companies representing businesses damaged by the blast.
Until Tuesday, investigators had been extremely tight-lipped about what might have caused the explosion and inferno that wiped out parts of the town of West, Texas.
Attention had focused on the presence at the plant of large quantities of ammonium nitrate, a dry fertilizer mixed with other ingredients and applied to crops.
Ammonium nitrate also is a possible ingredient in a bomb and was used by Timothy McVeigh in 1995 to blow up a federal building in Oklahoma City, killing 168 people.
West Fertilizer disclosed to a Texas state agency that it had 270 tons of ammonium nitrate on hand at the plant last year. There also had been persistent rumors that a rail car delivered to the plant by Union Pacific full of ammonium nitrate might have caught on fire and caused the blast.
But Kelly Kistner, assistant Texas state fire chief, ruled out the rail car of ammonium nitrate as the cause.
"What I can tell you today is that railcar that there's been questions about, that was full of ammonium nitrate, is not the cause of the fire or cause of the explosion. It is a victim of that explosion," said Kistner.
Union Pacific had confirmed that it delivered a rail car to the plant on April 15, two days before the blast, but declined to detail what was inside.
A spokeswoman for Union Pacific, Raquel Espinoza, said the railroad did not own the rail car or its contents.
"Photographs taken after the incident show the rail car lying on its side, largely intact, with no evidence of it being directly involved in the explosion or fire," she said in a statement emailed to Reuters on Tuesday.
"The car was knocked over by the explosion, resulting in some of its cargo being spilled. There are no visible signs of the cargo being burnt. Most of the cargo appears to have remained inside the rail car," Espinoza said.
The statement by Kistner on Tuesday did not completely eliminate ammonium nitrate as a possible cause of the blast because investigators have not commented on the stocks of ammonium nitrate other than the material in the rail car.
More than 70 state and federal agents are going through the scene "shovel by shovel," looking for the initial heat source, Kistner said.
The lawsuits, the first of what are expected to be many against the parent company of West Fertilizer, Adair Grain, accused the company of negligence. The plant is owned by Donald Adair, a longtime farmer in the area who bought it in 2004. Adair also owns the grain business and farms some 5,000 acres of cropland and pasture in the area.
A spokesman for Adair said the company declined to comment on the lawsuits.
Funerals for the dead were set to begin in the small farming town of 2,700 people on the Interstate highway between Austin and Dallas known for its Czech heritage.
A 31-year Dallas Fire Department Captain, Kenneth "Luckey" Harris Jr., 52, who was killed when he rushed to the scene of the blast to help, will be remembered on Wednesday at St. Mary's Catholic Church of the Assumption.
President Barack Obama will attend a memorial on Thursday in nearby Waco, Texas for all of the paramedics and firefighters killed in the explosion.