Alaska ? For five days or more, crude oil oozed from a pipeline through a corrosion hole about the size of a pencil eraser, silently spreading underneath the snow in what would become the biggest spill ever on Alaska’s North Slope.

Ultimately it wasn’t the pipeline’s leak-detection systems that discovered the spill on March 2.

It was an oilfield worker who caught a whiff of the petroleum.

Industry watchdogs say the spill was preventable and should have been detected more promptly, and they blame cost-pinching practices at BP, which runs the Prudhoe Bay operation.

State environmental regulators say the spill will lead to fines and possibly stricter pipeline regulations in Alaska.