Among the witnesses is Caltrans engineering geologist Mike Morgan, who will describe concerns he has with the way testing was performed on various concrete structures on the bridge, including the foundations. "He, similar to the experience of the other witnesses, will suggest that when he brought his concerns to management, they were dismissed," said the Senate briefing.

The discussion will also cover welds in bridge components manufactured in Chila and the problems with high-strength steel bolts and rods in the bridge that threatened to delay the bridge's opening.

The report and background document are available from the Senate committee's website, http://stran.senate.ca.gov/committeehome: