Demolition has begun on Mulholland Drive bridge in Los Angeles, closing California freeway 405 between the 10 and 101 highways, officials said. Highway officials closed the freeway at midnight Friday, forcing tens of thousands of people to find alternate routes to their destinations this weekend while crews demolish the southern half of the bridge, the Los Angeles Times reported Saturday. Officials plan to have the heavily used 10-mile stretch of highway between the San Fernando Valley and the Westside open in time for the Monday morning commute. On a normal summer weekend the closed highway carries about 500,000 vehicles through the Sepulveda Pass. "The day is upon us," Los Angeles Mayor Antonio Villaraigosa said Friday. "We've been stressing to the residents of Los Angeles for three months now: Los Angeles has to plan ahead, we hope you will heed our advice." "It's really going to depend on you," Villaraigosa said. "A lot of talk about 'Carmageddon,' and I expect, because of the unprecedented effort … we believe this will go very, very smoothly, but it does depend on you." The other half of the bridge will be removed later, necessitating another road closure. The demolition is part of a larger, $1-billion freeway improvement project that includes adding a northbound carpool lane.