An alleged drunk driver plowed into a crowd celebrating the Fourth of July in a New York City park, killing three and injuring seven others, with one witness recalling the carnage: A gray Ford F-150 sped through the intersection of Water Street and Jackson Street in Manhattan, blew through a stop sign Thursday, jumped the sidewalk and then barreled through the crowd at Corlears Hook Park. Four people were pinned under the pickup. “I can’t get the screaming out of my head,” a witness told the New York Post . Three people were killed: a 59-year-old woman, a 38-year-old man and a woman in her 40s…