The April 17 blast killed 15 people, injured 200 and levelled part of the town of West, which has a population of around 2,800.
The explosion was so powerful that it registered on the Richter scale as a 2.1 earthquake, and debris from it was found up to 2.5 miles away.
Officials said three possible causes of the fire were a malfunction in the plant's 120-volt electrical system, a golf cart that may have given off a spark, or it may have been started intentionally.
Investigators said between 28 and 34 tonnes of ammonium nitrate exploded in two blasts just milliseconds apart.
Another 20 to 30 tonnes also stored on the site did not explode. A nearby railcar holding an additional 100,000 tonnes of ammonium nitrate was damaged.
Mr Perry said: "This tragedy has shown the world the definition of compassion, from volunteer firefighters across the state rushing to help their colleagues at the scene, to friends, neighbours and Texans stepping in to help those who lost so much in the blast."
SOURCE : http://news.sky.com/story/1092033/texas-fertiliser-blast-arson-not-ruled-out






