A glass panel from a seventh-floor balcony in Queens suddenly plunged to the sidewalk Monday, injuring a 9-year-old girl and a 45-year-old man, authorities say. Firefighters responded to the Beech Avenue building in Flushing around 6 p.m. for a report of an unstable facade. They encountered the two victims, both of whom were taken to a hospital with back and neck pain. They are expected to be OK. Winds were fairly strong at the time, but officials say there’s no indication a gust had anything to do with the incident. Department of Buildings investigators were called to the scene. They couldn’t determine why the glass shattered, nor could they determine whether the incident may have revealed a possible systemic issue that might impact the glass railings of the building’s other railings. The property owners were issued a violation for failure to maintain the building. DOB said its agents also ordered property owners to hire a professional engineer to conduct structural stability inspections of the other glass buildings.