A 15-year-old boy is being hailed a hero after rescuing a woman whose car plunged into Lake St. Clair on Tuesday. John Agnello was fishing with his mother near the Lake St. Clair marina when he witnessed the car fly through the air and sink into the deep water. “I just saw a car flying through the air,” Agnello told WLIX 10. “It was about 45 feet deep in the water, that far.” Read: United Airlines Flight From Houston To Boston Diverted Due To Onboard ‘Biohazard’ Incident Without hesitation, Agnello and another bystander jumped into the water and swam towards the sinking car. The water pressure…