It was a harsh wake-up call at 4:20 a.m. for about 500 guests at the Sheraton-Anaheim hotel. The purposely annoying noise of smoke alarms filled the four-story "executive building," rousting guests out of their slumber. But it was a false alarm. Anaheim Fire Battalion Chief Steve Magliocco said one or more people took hotel fire extinguishers and discharged them in a hallway. The powder emitted by the extinguishers was picked up by the smoke detectors, which let out their blasts, he said. John Schulz, Sheraton's general manager, said people were jolted out of bed by the noise. All 265 rooms in the building were full, "almost completely double occupancy." The evacuees were ushered into the coffee shop, which opened early with complimentary juice and coffee.