A person was found dead Thursday morning on the southbound 57 Freeway in Diamond Bar.
Officers responded at 1 a.m. to reports of a body in the slow lane of the freeway near Pathfinder Road, according to the California Highway Patrol.
Information was not immediately available on the identity of the man, who was in his 50s, or on what led to his death.
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All southbound lanes of the freeway, except the carpool lane, were closed until about 4 a.m., when the roadway was fully reopened, the CHP said.