Evacuations ordered as An explosion in an underground electrical vault in the Fairfax Village area on Friday left four people with minor injuries, shattered glass at nearby businesses and left thousands without power on a sweltering day, just as many customers had service restored from an earlier outage. Firefighters were sent about 1 p.m. to the 8400 block of West Beverly Boulevard to tend to the injured, according to the Los Angeles Fire Department. Four people -- three males and a female, all customers at two nearby businesses -- were evaluated at the scene and declined to be taken to a hospital, according to the fire department. Reports from the scene showed jagged shards of glass strewn among booths and tables of an affected restaurant. As a result of the blast, Cedars-Sinai Medical Center put emergency power generators into use and announced that "non-emergency procedures may be postponed." The explosion occurred as Los Angeles Department of Water and Power crews worked to restore service following an outage that began Thursday afternoon and cut electricity to about 3,500 customers, according to the utility. This afternoon's failure involved "a different circuit in the same vault, serving the same community ... ," the DWP reported. "The force of that incident caused windows to shatter in front of a business located near West Beverly Boulevard and North Alfred Street." The blast appeared to have caused "only cosmetic damage and no structural compromise," the LAFD reported. "The 3,500 customers without power from the initial outage remain without power," according to a DWP statement released this afternoon. "The latest failed circuit has also resulted in additional customers experiencing an outage." The total number of customers now affected was not immediately available, nor was an estimated time of service restoration, according to the DWP, which deployed additional personnel to the scene. Crews had restored power to all but about 200 of the customers affected by the initial outage, which affected The Grove shopping and entertainment center, where stores had been closed pending the completion of repairs. Service was first interrupted about 3:30 p.m. Thursday, affecting an area that includes the Park La Brea apartment complex on Third Street, across the street from The Grove.