In a statement to ABC News, Norfolk Southern said it "deeply regrets the accident" and is it was working on new technology to improve "an already-superior safety record."
The train was running in what's known as dark territory.
Forty percent of the country's tracks, primarily in less-used areas, have no signals and no warning systems.
Every year there are 1.7 million carloads carrying some of the deadliest chemical agents known to man, crisscrossing the nation--- a number that's rising.
"It's a question of when again. I mean it's going to happen again. There are rail crashes almost every week in this country," said James P. Hoffa, the president of the Teamsters Union, which includes the railroad workers.
"They're just rolling the dice that maybe there won't be a rail wreck. Maybe we'll just get by if we go on the cheap, and that's the thinking of the industry."
Last year alone, there were 846 accidents involving trains carrying deadly chemicals -- a number that's gone up over the last four years.
Thirty-six of those accidents involved the release of toxic chemicals into the air.
A lack of signals isn't the only cause of potentially lethal accidents. Human error is the single largest cause of train accidents . In 2004, three people died in Macdona, Texas in a train collision that released deadly chlorine gas. The National Transportation Safety board determined that the probable cause was fatigue of the train crew .
Track defects are the number two cause of train accidents -- accounting for more than one third of all train accidents.
Peggy Wilhide, spokeswoman for the American Association of Railroads, says the industry is trying to deal with a problem that's been forced upon it.
"We are really adamantly pushing Congress and chemical producers to look at using safer chemicals rather than the toxic chemicals that we are required by the federal government to transport now," Wilhide said.
"We have a 99.997 percent safety record. … A 100 percent safety record is what we strive for."
Wilhide says the industry is asking tank-car makers for stronger cars. She also says railroad companies are experimenting with a new high-tech communication system in two test areas.