Just before midnight Engine 9, Medic 9a, Car 109, and Ladder 5 responded to a reported overturned tractor trailer in the 6200 block of Godwin.  Car 109 (Parsons) arrived to find a tractor trailer overturned on its roof with a utility pole (determined to be telephone lines) down on the trailer.  M9a arrived and began care of the trucks occupant who had self extricated prior to our arrival.  Engine 9 arrived and began checking the vehicle for hazards, the truck was carrying lumber and other construction materials.  Ladder 5 was cleared prior to arrival.  The engine crew secured the batteries, provided scene lighting and remained on scene until the towing company could upright the vehicle.  As the vehicle was being uprighted one of the saddle tanks ruptured causing an estimated 50 gallons of diesel fuel to spill.  Crews went to work containing the spill.  Notifications were made and the scene was turned over to the cleanup contractor.  All units cleared just before 0500, Car 109 had command.  E29 remained staffed in quarters while the other units were committed.