Summary: Engine 48 was dispatched to respond to a smoke detector alarm at 8555 San Ysidro Avenue, near the intersection of Leavesley Road and Los Animas Avenue in Santa Clara County, California. The alarm was reported at the Phase 5 outlet, identified as 'Packless Finishment,' with no suite or building number provided. Attempts to contact the responsible party and security were unsuccessful. The alarm remained active, and the presence of transients in the building was noted, but no immediate evidence of fire or injury was reported.