Officials of the Health and Safety Authority and Garda forensics experts today will begin an investigation into an explosion and fire which destroyed a unit of the Irish Industrial Explosives plant at Enfield, Co Meath, last night. The incident occurred shortly before 9 p.m. and three units of the fire brigade from Maynooth and two from Trim attended at the scene. Firemen, assisted by staff at the plant, moved potentially hazardous materials to safer locations and sprayed storage tanks in containing the blaze. No one was hurt.