A Sigalert was issued Friday afternoon on the eastbound 60 Freeway in Moreno Valley, at one point shutting down all eastbound lanes, the California Highway Patrol said.
A semi-truck that was carrying an oversized load struck the overpass at the Indian Street exit, causing chunks of concrete to fall in the lanes.
Officials were yet to determine the extent of the damage although no drivers were believed to be injured.
By 5:11 p.m., only the carpool lane was open on the eastbound side of the freeway.
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Officials did not say when all the lanes will reopen.
