Battalion Chief Jim Zuluaga of the Tacoma Fire Department at first called it a "very volatile situation," but the danger lessened as the size of the leak decreased and fumes dissipated.
He said the tanker truck was transferring 2,500 gallons of liquid propane to another tank, when the hose broke and began dumping propane into the atmosphere. The truck's engine was still idling as billowing white clouds of propane fumes wafted through the area.
The area was immediately evacuated.
About 25 firefighters responded to the leak, in the 4000 block of Marine View Drive in Tacoma.
Crews monitored propane levels in the atmosphere until they dropped to safe levels, then closed the valves on the tanker and secured the scene.