WASHINGTON - On the eve of the nation's noisiest holiday, the Consumer Product Safety Commission responded to growing fireworks injuries by quietly reopening the question of how it should police explosives for backyard entertainment. Without a public meeting, the three commissioners voted unanimously by ballot late Friday to begin a study of whether to tighten their regulation of fireworks, commission spokesman Scott Wolfson announced Monday. Their notice seeking public comment will appear soon in the Federal Register. The notice cited a disturbing increase in injuries and a decrease in compliance with safety regulations as reasons for the first major review...