Fifteen people -- most of them first responders -- died in the April 17 explosion at the West Fertilizer Co. facility in West, Texas, 20 miles north of Waco and 70 miles south of Dallas.
At least 200 others were injured, and the estimated insured damage is $100 million, the Insurance Council of Texas said.
Should the company be found negligent in the explosion investigation, the $1 million in liability coverage would only cover a fraction of the damages, including the destruction of an apartment complex and damage to a nursing home, school and several hundred homes, The Dallas Morning News reported Friday.
The West Fertilizer Co. said it had 270 tons of ammonium nitrate on site at the end of last year.
"A million dollars is a pathetic amount for this type of dangerous activity," said Tyler, Texas, lawyer Randy C. Roberts, who has filed two negligence lawsuits on behalf of victims.
"If you want to drive a truck down the interstate, you've got to have $750,000 in coverage, even if you're just carrying eggs," he said. "But if you want to put this ammonium nitrate into this town next to that school and that nursing home and those houses, you're not required to carry insurance."