The thefts have been occurring throughout the city with no geographic pattern, police said.
The stripping of the copper has resulted in multiple power outages that have affected residents and businesses near the crime scenes, police said.
The copper that was removed served as the “neutral leg” that connects underground transformers, which churn out the high voltage electricity that powers the city, police said.
Police believe the copper thieves’ actions have taken place between the hours of 2 and 6 a.m., when they would park a vehicle at a curb alongside a targeted grated sidewalk vault, remove the manhole cover and descend into the vault, police said.
The suspects would then use what police believe to be ratcheted bolt cutters to cut the copper wire, which is over one inch thick, and remove it. Earlier thefts indicate the use of a hack saw, police said.
Police said the thieves have also previously uncoiled and stolen copper grounding wire from underground transformers.
The thefts seem to be in areas that have no overhead wires and are usually located in light industrial areas, police said.
Previous locations of the thefts include the 4500 and 4900 blocks of Mission Street, the 400 block of Jackson Street, and the intersections of Gough and O’Farrell streets, Turk Boulevard and Masonic Avenue, and 8th and Minna streets, police said.
Anyone who witnesses suspicious behavior in the area around underground vaults is encouraged to call San Francisco police immediately by dialing 911 or contact PG&E’s 24-hour security control center – which is staffed 7 days a week – at (800) 691-0410.
Due to a very high risk of electrocution, police discourage all officers and citizens who witness possible copper thefts from attempting to enter a vault that is potentially being robbed.