Los Angeles County this week began a nearly half-million-dollar project aimed at preventing earthquake damage to a railway bridge in Glendora, Calif., officials said, according to the San Gabriel Valley Tribune.

Work on the bridge, located on Route 66 between Loraine and South Lone Hill avenues, is expected to last about 70 days, according to Los Angeles County Department of Public Works Construction Office Engineer Pirouz Bozorgnia.

"It's basically strengthening of steel-based frames and footing, painting structural steel and fastening bearings," Bozorgnia said. "It's seismic rehabilitation of the bridge."

The bridge accommodates two freight trains per day and is part of the Metro Gold Line, Metrolink officials said.

The county has been in contact with Glendora city officials since 1998 to get the project started, Bozorgnia said.

Bridges are inspected at least once a year, according to Los Angeles County Department of Public Works spokesman Mike Kaspar.

The seismic retrofitting program came about after the magnitude-6.9 Loma Prieta earthquake that struck the San Francisco Bay area in 1989, Kaspar said.

"Basically the state of California said `we need to go and do a full look at all the bridges in the state and L.A. County was given supervision over our county to look at them,"' Kaspar said.

The project on the Route 66 bridge will shut down one lane on the street in each direction, Bozorgnia said. For the first stage of the project, the inside lane in each direction will be closed and for the second half of the project, the outside lanes will be closed, he said.

"Initially they're going to be working to add columns, so we have to close lanes closer to the median to provide safety for workers," he said.