Ronnie James Wilson Sr. was pronounced dead at the scene, the Jacksonville Times-Union reported.
Lt. Bill Leeper of the Florida Highway Patrol, which is investigating the death, said that four cars, all with emergency lights and sirens on, were responding to the emergency call. Witnesses said that Wilson stepped out into the street in front of the third car.
The dog had not been seen Wednesday. Wilson's family said that hope the pit bull, Lady Beast, is able to make her way home.
Lachawn Richo, Wilson's daughter, described her father as someone who cared for his neighbors and his elderly mother after raising a family. She told News4Jax.com she is especially worried about her grandmother.
"My heart just went out to her last night," Richo said. "She was sitting there saying, 'That's my only child! That's my baby! He's gone!'"