His family said the woman was upset that he had accidentally bumped into the child.
The girl's mother allegedly exploded shoving Rodriguez to the ground and then picked up a brick and hit him in the face with it.
"And then when one of the witnesses comes out of her vehicle and starts screaming at her, four other guys come in and start kicking on him", Mendoza told KTLA.
The Los Angeles Sheriff's Department is still investigating.
Rodriguez was eventually assisted by a witness who called 911, and the suspects ran away.
He was left unable to walk along with a broken cheek bone, bruised ribs and head injuries, the station reported.
"We are concerned, especially with the type of crime they committed", he told KTLA.
Graphic video footage shows Rodrigo Rodriguez looking dazed and bloodied after being attacked while visiting family in LA on July 4.
The GoFundMe page for Rodriguez has already doubled its original goal of $15,000.
Rodolfo Rodriguez's family told the ABC affiliate in Los Angeles that he had just finished dinner and was going on his daily walk around the block near his home when he was confronted by a woman walking with a child.
The page has been shared just under 7,000 times on Facebook. The girl's mother supposedly told the man, "Go back to your country, why are you here, bad things", according to The Hill.
Misbel Borjas was driving by when she saw the woman hitting Rodriguez repeatedly in the head with a concrete block, she said. Borjas tried to defend the man, but she said that the woman threatened her with a brick. Mendoza told the outlet.
Los Angeles authorities are searching for several suspects in the beating of a 92-year-old man out for a walk on the Fourth of July. "What kind of harm can he mean to anyone?" Mendoza asked. "That's why we're still in shock, as you can see he's badly injured".
A witness began recording the incident involving Rodriguez and a woman and four men. Sheriff's Det. Carlos Cueva said no one had been apprehended as of Monday evening.