So what stopped a tunnel boring machine under Seattle last December? A boulder? An alien spaceship? Richard Sherman? Nope. In fact, it wasn’t anything the machine was facing at all. Instead, those involved in the construction of the future underground highway concluded that a mechanical failure within the TBM is to blame. Inspectors found damage to a sealing system that protects the machine’s bearings, which allows the machine to spin and cut through soil. Unfortunately, any fix would be a nuanced affair and could take months, though officials assert that taxpayers will not be on the hook for delays. Closer to home, a section of the new Oakland Bay Bridge that was designed to be waterproof sprung leaks during the recent storms, according to transportation officials.