SAN ANTONIO -- A teenager struck Friday morning by two cars outside of Stevens High School died Friday afternoon, hospital officials said.

Police said 16-year-old Christian Lozano was crossing the street at Potranco and Dugas roads about 7:15 a.m. when he was struck by a pickup truck.

When the driver stopped to check on the victim, the teenager stumbled back and was hit by a car, police said. The driver of the second vehicle did not stop, police said.

"He was here long hours before school and after getting ready, and he was known for helping other students if they were down. He was a positive force in their lives," Stevens High School prinicipal Harold Maldonado said. "(He) always had a smile on his face and (he was) someone, who if you saw his yearbook and saw his face, you'd go, 'Oh, that's him,' because everybody knows him."

Lozano was active in a variety of clubs and was likely going to school early to work on an extra-curricular activity, Maldonado said.

Police said Lozano may have been wearing earphones when he was struck by the vehicles.