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. Eyewitness video shows the man on the ground moments after the attack, dazed and with blood streaming down his face.

The woman who recorded the video says he was struck in the head several times with a piece of concrete.

Investigators say the assault happened as Rodolfo Rodriguez passed a woman as they walked on a sidewalk in the Willowbrook neighborhood. Authorities say a group of men joined in the attack.

The victim’s grandson, Erik Mendoza, said Rodriguez suffered a broken cheekbone and severe bruising. He added his grandfather speaks little or no English and didn’t understand why he was being attacked. “I’m just overwhelmed how anybody can do this to a human being at all,” Mendoza said. “He’s 92 years of age. There’s no harm that he meant for you to treat him the way you did.”

According to another witness, the little girl’s mother shouted “bad things” at Rodriguez as she beat him with her hands and then a chunk of concrete, including, “go back to your country, why are you here?”

The witness said she took her phone out and got a photo of the woman, who appears to be holding a piece of concrete as her child stands nearby.

Mendoza said he’s still stunned and struggling to understand the attack on his grandfather, who has U.S. citizenship.

“That’s the lesson you’re going to give your child, for you to hurt elderly people because they bump into you?” he said. “I just want to know what was going through her mind.”