Workers, safety officials and investigators are still not combing through the aftermath of the Plymouth natural gas explosion site, but are securing the area. (Photo courtesy of KNDU-TV)

According to our news partner KNDU-TV,  officials are using a technology called FLIR, or Forward Looking Infrared Radar, to scan all the areas of the site.  FLIR can display liquified natural gas that is burning, but is unseen to the human eye. 

This scenario is similar to issues faced by Indy Car drivers, who use methanol for fuel.  There have been incidents when fires in the pit ignited the gas, but it cannot be readily seen with flames like regular fuels.

Investigators continue to interview any and all Williams Co. workers who were at the site when the early Monday morning explosion occurred.  And although it may seen like adding insult to injury, federal regulations require all workers at the site to be drug tested following major incidents such as this.

Once the facility is deemed to be safe for human entry, the actual physical investigation into what exactly caused the rupture and explosion can begin.  Due to safety reasons,  no photos of close-up at explosion site are readily available.