Around 1:45 p.m. Friday, Benjamin Walker awoke to the sound of firefighters in the backyard of his Sanford Street home.  He jumped out of bed, looked outside and saw the oak tree on the fence line of his yard burning. “Holy shit!” he said aloud. Still in a post-nap daze, he scrambled to figure out what to do next. “I’m still waking up. I get my stuff together and get out there,” he told Oakland North Saturday. “The firefighters tell…