The afternoon was sultry, and along the deserted block of neat brick row houses in the Cobbs Creek section of West Philadelphia, an ominous calm had descended. Suddenly the thwack of rotors broke the silence. A blue-and-white Pennsylvania State Police helicopter arced in low over the roof-line. It made several passes over the street, then hovered 60 ft. above the two-story home at 6221 Osage Avenue. In the helicopter cabin, Lieut. Frank Powell, chief of Philadelphia’s bomb- disposal unit, hefted a canvas satchel holding two 1-lb. tubes filled with a water-based gel explosive. After lighting its 45-sec. fuse, Powell leaned out of the helicopter bay and dropped the device on the roof. His target: a fortified, bunker-like cubicle about 6 ft. square and 8 ft. high. All was quiet for the next half-minute or so. Huddled on rooftops and in the doorways of nearby row houses, flak-jacketed police officers put their hands over their ears. Then there was an orange flash and a powerful explosion that sent wood, metal and a cloud of dust flying into the air. Said a resident of adjacent Pine Street: “The blast didn’t just shake the windows, it shook our entire house.” From behind police lines, residents of Osage Avenue, who had been evacuated the previous evening, watched in disbelief as a column of thick black smoke rose from the rooftop. Minutes later flames appeared, mere flickers at first, then a mountain of orange. The fire raged unchecked as officials delayed responding so the flames would burn through the roof and drop the bunker. Then they planned to drop tear gas through the opening. Just so, they hoped to flush out the occupants of the house, a bizarre radical cult known as Move. But the strategic fire soon became a phantasmagoric inferno. Half an hour after the explosion, firemen finally moved to control the blaze. There was a rattle of gunfire in or around the Move compound, and according to some reports, the police returned it. Ordered back out of range, fire fighters watched as the flames spread first to adjacent houses, then down the street. On Pine Street, Barbara Johnson, wife of Philadelphia Daily News Staff Writer Tyree Johnson, viewed the blaze from her front porch. “You could see the flames, 20, 30 feet above the rooftops, reaching over like blazing fingers, igniting houses first on Osage, then adjacent houses on Pine. Soon a solid wave of flame was sweeping down the street.” Suddenly a naked child dashed from the flaming wreckage near the Move headquarters. A team of policemen charged in pursuit. “They grabbed him by the shoulders and just carried him off,” says Johnson. “His feet kept paddling, like he was walking on air.” The terrified child was probably Birdie Africa, 13, who with Ramona Africa, 30, was one of the two known survivors from the Move compound.