JACKSONVILLE, Fla. (AP) _ Firefighters using an unproven foaming method smothered a gasoline storage tank fire that had burned for five days.

A worker was killed when the fire broke out Saturday.

Despite snuffing the flames Wednesday night, firefighters had to keep watch at the Steuart Petroleum Co. yard because gasoline continued to overflow the tank, officials said.

Firefighters had tried foam several times without success. On Wednesday, they used an unproven technique in which they sandwiched the blaze by piping foam into the top and bottom of the tank.

Firefighters let out a cheer when the flames died out. ''God, is it quiet,'' said fire department spokesman John Peavy.