A woman was reportedly killed after being struck by a box truck at Market and Powell streets in downtown San Francisco Friday morning, near the cable car turnaround.

The collision reportedly happened around 8:20 am Friday, according to police scanner reports on the Citizen app. An initial 911 call reported a female pedestrian who suffered a fatal head injury after being struck by "a bus" on Market Street near Fifth Street, according to police.

KRON4 reports via the SFPD that the person who was killed was on a scooter, but then reports it was a "vehicle vs. pedestrian crash." And the Chronicle reported that the woman died in a "high velocity crash," and a scooter was found beside her, but it remained unclear how the crash occurred.

Update: ABC 7 reports, via a witness, that the woman was riding a scooter down Market Street when her tire got stuck in a streetcar track — a hazard many bicyclists are familiar with. The woman then apparently crashed and fell onto the roadway, where she was struck by a box truck, the witness said. It's now unclear if the box truck may have fled the scene, but the SFPD says they have located the driver.

Video from the scene showed a tarp and tent being put up around a person down in the sidewalk at Powell Street, in the middle of the Market Street block between Fourth and Fifth streets. ABC 7 also had footage of the victim's helmet lying in the street.

The SF Department of Emergency Management sent out an alert warning everyone to avoid the area of Market and Fifth streets due to police activity.

The SFMTA reported on a "Non Muni collision" in the area of Market and Fifth Street which has shut down surface Muni service in both directions. The F-line streetcar and the 5R, 7, and 9R buses are all affected.

Muni riders are being advised to use the subway between Embarcadero and Van Ness to avoid the situation. Inbound buses are being rerouted via Fifth Street and Mission Street, returning to their regular route at Market and Third streets.

This story has been updated with the witness information, clarifying that the victim was on a scooter and was not a pedestrian in the crosswalk.

Top image via Citizen app