Image of water pooling on the runway at SFO after a rainstorm. Experts say pooling is a sign of differential sinking.
Image of repaired alligator cracks on the runway at SFO. Experts say these cracks are signs of differential sinking.
Image of water pooling on the runway at SFO after a rainstorm. Experts say pooling is a sign of differential sinking.
Image of repaired alligator cracks on the runway at SFO. Experts say these cracks are signs of differential sinking.