On Friday, an open-air, double-decker tour bus in the Richmond District struck some low-hanging power lines and caused serious injuries to four tourists in their 60s. One of the victims is said to have suffered life-threatening injuries.

The incident happened Friday afternoon around 3:15 p.m. at Geary Boulevard and 12th Avenue. The four victims were all taken to S.F. General, and the variety of their injuries is not clear.

There's little further information about the incident, and we don't know who the bus operator was, or whether this was a regular route for the bus and the wires were not previously so low-hanging.