SLOW MOTION DISASTER IN SOUTHERN CALIFORNIA WHERE A LANDSLIDE CRISIS POSES AN ACCELERATING THREAT. MORGAN CHESKY IS ON HAND. AND MORGAN, THE SCOPE HERE IS PRETTY MASSIVE. >> Reporter: YEAH, LESTER, IT ABSOLUTELY IS. UNFORTUNATELY, THIS IS JUST A GLIMPSE OF SOME OF THE DAMAGE THAT HAS ALREADY BEEN CAUSED HERE. TONIGHT STREETS ARE SHUTTING DOWN AND SOME HOMES ARE BORDERLINE UNREACHABLE, ALL AS THIS CRISIS DEEPENS BY THE DAY. TONIGHT, A STATE OF EMERGENCY ON THE CALIFORNIA COAST. THREATS OF LANDSLIDES FORCING DRASTIC MEASURES IN THE SEASIDE COMMUNITY RANCHO PALOS VERDES WHERE STREETS ARE CLOSING AS HOUSES THEY CRUMBLE. >> WE HAVE MADE THE VERY DIFFICULT DECISION TO DISCONNECT POWER INDEFINITELY. >> Reporter: OFFICIALS WARNING EVACUATION WARNINGS AFTER THE UTILITY PROVIDER CUT POWER TO MORE THAN 240 HOMES. >> THIS HAS GIVEN US 30 DAYS. SO WE GET READY FOR IT. >> Reporter: SOUTHERN CALIFORNIA EDISON BLAMED SHIFTING SOIL FOR A FALLEN POWER LINE, SPARKING A RECENT FIRE. THE SUDDEN SHUTOFF ADDING TO AN ALREADY GROWING NIGHTMARE FOR RESIDENTS LIKE MIKE HUANG. YOU'VE LOST POWER. YOU'VE HAD YOUR GAS LINE CLOSED OFF. YOU HAVE INTERMITTENT WATER. WHY HAVEN'T YOU LEFT? >> WELL, WE DON'T REALLY HAVE AN OPTION. LEAVE AND GO WHERE? >> Reporter: GEOLOGISTS SAY THE SLIDE RATE HAS ACCELERATED DUE TO BACK-TO-BACK WINTERS OF HEAVY RAIN, IN SOME AREAS MOVING MORE THAN A FOOT A WEEK, EVEN CREATING AN ENTIRELY NEW COASTLINE. >> THIS IS AN EVER CHANGING CRISIS AS WE NAVIGATE THROUGH THIS, AND WE NEED TO BE PREPARED. THAT IS THE ONLY WAY WE CAN STAY SAFE. >> Reporter: HUANG HAS WATCHED ONE OF SEVERAL EARTHEN CRACKS CHEW THROUGH NEIGHBORS' PROPERTY. >> IF WE DON'T GET HELP, EVENTUALLY THIS PLACE WILL BE GONE. >> Reporter: DREAMS DASHED FROM A SLOW MOTION DISASTER. MORGAN CHESKY, NBC