Dive summary:

• It turns out that post-tensioning of a new pontoon bridge across Lake Washington, east of Seattle, caused stress that the design of the concrete pontoons had not accommodated, and some of them developed cracks that a review panel said could eventually leak and sink them.
• Each pontoon is 360 feet long and four had been moved into place before a state panel in October concluded that it was the state's own design flaw that caused the problem, leading to new work that may add tens of millions of dollars to the price.
• Transportation Secretary Paula Hammond said the pontoons are sound despite the flaw, but the report found a .03-inch in one that it said could be big enough to leak, and inspection of the first pontoons found cracks as long as 10 feet.

From the article:

Hammond made a public statement that "schedule pressure … drove many poor decisions" in a process filled with communication deficiencies and confusion regarding responsibilities. ...