Because the monster wasn't under the bridge anymore.
The 4G was the monster under the bridge. 4g position welding
He moved in a steady, rhythmic weave: two steps forward, one tiny pause to let the puddle freeze. Crackle-crackle-pause. Crackle-crackle-pause. His gloved hand trembled, but he didn't break the arc length. He was balancing a teaspoon of liquid starfire on the underside of a steel cloud. Because the monster wasn't under the bridge anymore
He had tamed it.
He ran a second pass. Then a third. A fourth. Crackle-crackle-pause
But ? Overhead.
The trick, he realized, wasn't to push the rod up into the gap. It was to hold a tight arc. So tight the flux created a surface tension bubble, a little glass ceiling that held the molten metal in place against the pull of the earth.