SACRAMENTO, Calif. (AP) — Senior state transportation officials on Tuesday acknowledged serious problems, including a culture of secrecy, during construction of the $6.5 billion eastern span of the San Francisco-Oakland Bay Bridge. But they denied that employees were reassigned or lost their contracts after raising red flags about inferior construction work.

“Yes, mistakes were made,” Transportation Secretary Brian Kelly testified during a legislative hearing. “Building a bridge like this is a human endeavor. Human beings are fallible, and that fallibility was evident on this project as on any major infrastructure project.”