There were as many as 80 aftershocks, including one that was recorded at magnitude 4.6.

Tony Tavares, director of the California Dept. of Transportation, added that the agency had dispatched a “strike team” of bridge inspectors and engineers to assess bridges, roads and major structures. One bridge in Humboldt County, the Fernbridge, suffered damage, Tavares said. The 1,320-ft concrete arch bridge carries State Route 211 over the Eel River between Ferndale and U.S. Route 101. Officials closed the bridge to traffic while Caltrans inspectors assessed the extent of the damage.

Tavares issued a $6-million emergency order to bring on a contractor as quickly as possible. Caltrans hired Sacramento-based Myers & Sons Construction for the reconstruction work. It was mobilizing equipment and personnel to get on site the same day, he said. 

“Most likely we will shore that bridge and get it ready and open to public traffic, and then commence with final repairs of the bridge,” he said.

Infrastructure including water, power and gas lines were also damaged in the quake, Ghilarducci said. About 70,000 people lost power. A full assessment of the damage will take several days, he added.

“Earthquake damage is always a little bit more difficult to find because you have to get in and understand what the foundation looks like, where the cracks may take place,” he said.

Ghilarducci also noted that California's new early warning system pushed out alerts to 3 million people 10 seconds ahead of the quake.