In a plant explosion case typically liability is established by the use of experts. You look for an expert that has a long history of employment in the type of plant that’s exploded. If it’s a chemical plant you’re looking for an expert with a lot of history in the chemical industry. If it’s an oil refinery you’ll look for an expert who has a lot of experience having worked in the refineries during their life. Also many of the times in these cases US Chemical Safety board will do an investigation and those can be very helpful in establishing the background facts related to a plant explosion. The experts will take a look at all the facts and come up with an opinion as to what happened to cause the explosion in the particular type of case that you were involved in.