Caltrans says the bridge is safe, but they have crews watching it today to make sure.
VIDEO: Here's where concrete chunks on Richmond-San Rafael Bridge came from, fell
CHP says it was a 911 call that first alerted them to the problem after large chunks of concrete fell from the top deck to the lower deck of the bridge. At least one car was hit and damaged but no one was hurt.
It happened in a spot about a half-mile east of the toll plaza-which is on the Richmond side of the span.
Drivers who were stuck on the bridge when it closed were turned around by CHP and directed eastbound to exit the bridge.
The closure caused gridlock stretching for miles. Thousands of people had to look for an alternative route. Many headed to Highway 37 only to be stuck in a massive traffic jam.
RELATED: Bridge closure causes traffic nightmare for drivers in the Bay Area
The bridge closure was on and off for most of the day.
Caltrans came up with a temporary repair; they put a metal plate over the area to keep more pieces from falling.
RELATED: Source provides theory on why concrete is falling from Richmond-San Rafael Bridge
"Right now Caltrans has an emergency directors order what that does is clears away funds for Caltrans to do long term repairs. The metal plates are a short term repair," said Vince Jacala, Caltrans.
Officials say the bridge is safe to drive on, otherwise they would not have it open.
See more stories about the Richmond-San Rafael Bridge closure.