A sound wall is demolished on Sepulveda Boulevard, south of Sunset. For 2 1/2 years, residents of Westwood Hills have lived with the noise and shaking and lights from construction through the Sepulveda Pass. Much of the heaviest and loudest lifting is done at night, with the result that homeowners have had construction roar coming at them with the intensity of a diesel truck moving at 50 miles an hour 50 feet away. According to Caltrans, the noise of that diesel truck is equivalent to 86 decibels, the loudest level allowed at night under an agreement with homeowners.