Andres Telles, 31, was pressure-washing a tractor-trailer rig with his friends, Fidelmar Montero and Miguel Lopez, when the incident took place.
According to a witness the men were "underneath the trailer, and the lightning bolt hit."
Janet Suarez and her son, who live a few yards away from the scene, told WSVN they were inside their home when they heard a boom. They reportedly went outside and found the men on the ground.
"My mom was talking to 911, and then they were telling her what to do," said Suarez's son Dominic Rodriguez. "All I could think of was keep patience and try as best as I can, to try to keep him alive as much as I can."
Mother and son administered CPR, but weren't able to save Telles.
Montero and Lopez were taken to a local hospital and are listed in stable condition, according to the Miami-Dade Police Department.
Police are still investigating if the "individuals were directly struck by the lightning or the lightning struck the ground nearby," said Det. Robin Pinkard told WSVN.