The Chemical Safety Board updated Rep. Nick Rahall, D-WV, Thursday on the progress of their investigation into the explosion at the Little General Store in Ghent on Jan.30, in which four people were killed and five injured.

According to the Safety Board, the investigation is still underway and the investigators continue to interview those affected by this tragic incident. Evidence has been stored in a secure location. The next steps into the investigation will include moving the evidence to an environmentally-controlled warehouse that will allow for more in-depth testing procedures.

Jeff Wanko, lead investigator with the Chemical Safety Board noted the cooperation of the Little General Store, Thompson Gas and Ferrell Gas, as well as the WV State Fire Marshall's Office and local authorities.

"My thoughts and prayers remain with the victims of this tragic accident," Rahall said. "I thank the Chemical Safety Board for their cooperation and look forward to receiving further information as their investigation continues."

The Chemical Safety Board is an independent federal agency that investigates the causes of major chemical accidents and to try to help prevent similar accidents in the future. The agency was created by Congress in 1990 under the Clear Air Act Amendments. A typical Chemical Safety Board investigation takes six to 18 months to complete. During the course of an investigation, the CSB gathers testimony from a broad array of witnesses collects and tests chemical samples and other evidence and the site is carefully studied and documented.