A major nighttime accident brought traffic to a standstill in the southbound lanes of the Costa Mesa Freeway for more than an hour and left at least four people injured, according to paramedics from the Orange County Fire Department. A disabled car was rear-ended by another vehicle, backing up traffic for several miles near the interchange with the Santa Ana Freeway, according to a California Highway Patrol dispatcher. Initially two victims, one in critical condition and the other reported in serious but stable condition, were rushed to Western Medical Center in Santa Ana. A few minutes later, two other victims who had left the scene to seek help were found and transported by paramedics to the hospital, officials said. A CHP spokesman said officers were still trying to contact witnesses late Thursday night and were not available to provide details about the collision.