A suspicious package was found today at a light-rail train station in Norwalk, prompting closures of two Southern California freeways as investigators work to determine what is inside.

A backpack was found on the platform of the Green Line (search) station, which sits just east of Interstate 605.

Traffic is being diverted off the 605 and the eastbound car pool lane of the 105 Freeway.

The Los Angeles County Metropolitan Transportation Authority's Green Line is a surface light-rail route running east-west across the southern end of the county between Norwalk and Redondo Beach, with a stop near Los Angeles International (search).