In Altadena, turn north off of Loma Alta Road at the flashing yellow light, onto Chaney Trail. Drive uphill until you reach the chain link fence. Park there. (Make sure your car displays an Adventure Pass--you can get one in the post office section at Webster's.) Then walk and enjoy. I think those firefighters would want you to.
Be sure you're back out on Loma Alta Road by 8pm, by the way. The Fire Road is open, but not around the clock. My friends and I almost didn't make it the other evening before the gates were locked. I might have been able to climb the fence but I'd have had to leave the car overnight and Boz would have had to camp out.
The mountains in the photo were once forested with trees resembling the survivors in the foreground. Last fall, after the fire, miles of mountains were covered with gray ash. It'll be years before a forest covers them again, but at least now they're colored a hopeful green.
I posted about the Sunset Fire Road once before, about two years ago. That, too, was in the aftermath of a fire. It strikes me that no matter what befalls it, this is compelling terrain.