At least four people are injured, one of them critically, following an incident at the Serramonte Mall in Daly City involving a SamTrans bus that may have been out of control and crashed into over a dozen cars in a parking lot.

The crash happened around 11:50 a.m. Friday, as ABC 7 reports. A SamTrans bus apparently jumped a median and plowed through the parking lot, striking 16 cars and possibly hitting pedesrians as well. Four people were reportedly injured, on critically, and they were taken to SF General for treatment.

One witness in the parking lot, local podcaster Gina G, tweeted, "I think the bus driver maybe got a heart attack or had a seizure??? He apparently jumped over the left side of the median-- opposite side of the bus stop-- and crashed into the parking lot next to Wells Fargo Bank."

In video of the aftermath on the Citizen app, a mangled Target shopping cart can be seen under the front wheels of the bus.

Car Crash Involving Bus in Target Parking Lot @CitizenApp

556 Serramonte Blvd 12:43:34 PM PST

San Mateo County's North County Fire Authority tweeted that the sheriff is investigating the incident, and the cause behind the crash are still not known.

Residents and shoppers are being told to avoid the area of the mall parking lot.

We'll update you as we learn more.

Photo via Citizen App