An underground utility vault, the kind that occasionally explodes and sends a manhole cover flying, exploded this morning at 9:40 a.m. at the intersection of Mason and Cyril Magnin Streets, near Union Square. The Examiner reports that PG&E arrived at the scene and that several streets were blocked off as a result, but the incident did not lead to any power outages in the area.

San Francisco Police Sgt. Frank Fagan told the paper that the streets were blocked as a precaution because "These manholes covers are very heavy... [and] they could blow off."

SF had a spate of exploding manholes for several years, the most recent incident we reported on here having been in August 2016.

PG&E has been berated in the news recently following that major blackout several Fridays back, an incident over which many affected downtown business are expected to file legal claims.