(Added: WSB photo)

11:19 PM: SFD and SPD are responding to what’s described as a two-vehicle collision with four people hurt, at least two seriously. The location is the 1100 block of SW Spokane St. [map]

11:22 PM: This is now described via radio as being on the low bridge.

11:32 PM: The low bridge is blocked to traffic and we expect that’ll last at least a few hours for the investigation.

12:29 AM: The pedestrian/bicycle path across the low bridge remains open; our photographer walked it to get to the scene (photo added above). No new information; the bridge remains closed, and the Traffic Collision Investigation detectives have been called to investigate.

6:21 AM: Just in case you’re wondering – the bridge did reopen. No additional information so far about the victims or the investigation.

MONDAY UPDATE: We checked with SFD today. Two victims – both teenage boys – were taken to the hospital by SFD medic unit; the other two (no age/gender info) were taken by private ambulance; all four were described as being in stable condition.