More than one-third of schoolchildren are homeless in shadow of Silicon Valley

Tech economy is drawing new inhabitants and businesses but is contributing to dislocation, leaving families, teachers and even principals with housing woes

Every night for the past year or so, Adriana and Omar Chavez have slept in an RV parked in East Palo Alto, a downtrodden community in Silicon Valley.

On a recent morning before sunrise, they emerged on to the empty street. Omar showed his phone to his wife: 7.07am. "Shall I wake up the girls?" he said, his breath visible in the freezing air.