FILE PHOTO: An employee works as he participates in a drill simulating a fire incident at an underground gas storage facility near Poltava, Ukraine, June 15, 2016. REUTERS/Gleb Garanich/File Photo
FILE PHOTO: An employee works as he participates in a drill simulating a fire incident at an underground gas storage facility near Poltava, Ukraine, June 15, 2016. REUTERS/Gleb Garanich/File Photo