A 47-year-old man from the East Bay has been identified as the suspect driver in a horrific pedestrian collision in the Outer Sunset on Monday, and police now say he was high on prescription drugs and cannabis.

The suspect has been identified as Robert Green of Hayward, and police say he was going 60 miles per hour in a 25-mph zone, and he blew through a stop sign at the intersection of 24th Avenue and Santiago Street on Monday around 10:52 a.m.

The intersection is a four-way stop-sign intersection that sits at one corner of McCoppin Square park.

Two women in a marked crosswalk were struck by Green's car. One was killed, and the other was seriously injured. Neither of the victims have been publicly identified.

Green's car then crashed into a parked vehicle, and he sustained minor injuries.

As KTVU reports, Green remained at the scene and told officers that his brakes had gone out. Green was arrested on suspicion of vehicular manslaughter and he is expected to appear in court Thursday.

The SFPD now says that Green was intoxicated on prescription medication and cannabis at the time of the crash.

"This incident highlights the broader challenges in our city right now in keeping, ensuring safety on our streets for pedestrians and especially our most vulnerable, our seniors and families with kids," said Supervisor Gordon Mar in a tweet that caused a stir on Twitter.

As SFist reported Tuesday, local Twitter celebrity Mc "Mack" Allen, the Muni driver who went viral last year for his tweets dissecting the Muni fight scene in Shang-Chi and the Legend of the Ten Rings, began trolling/engaging with Supervisor Mar following this tweet about the collision.

"Your heartbreak and anger need to spend today focusing on where your priorities lie: with the expedited movement of cars or the safety and vibrancy of human beings. That means barricades, bollards, and streets closed to cars," Mack wrote, pointing out that Mar had pushed to curtail the pandemic-era Slow Streets program in the Sunset.

Mar is facing a challenger for his District 4 seat currently, Joel Engardio, and it remains to be seen if his board seat is secure, or if this event may sway some voters.

Previously: After Pedestrian Fatality In Sunset, Twitter-Famous Muni Driver Slams Supervisor Mar For Scaling Back Slow Streets