NEW YORK (CBSNewYork) — The search for a suspect continues in what police called “an unprovoked attack” on an 83-year-old man in the Bronx.

Valentine Hernandez had just crossed Westchester Avenue at Fox Street Monday afternoon when police said he was sucker punched by a much younger and much larger man.

The entire incident was captured on surveillance video. Hernandez fell to the ground and lost consciousness, suffering a laceration to his forehead and fractures to his nose and face.

Miguel Santos is now desperate to speak to his elderly father, who is in critical condition in Lincoln Hospital.

“Never seen him that way. He was just there unconscious,” he said. “It seems like he’s trying to wake up but he can’t. He can’t open his eyes, can’t open his left eye at all. It’s swollen shut.”

Hernandez has lived in the Longwood section of the Bronx for decades and was walking his usual route around the neighborhood.

“If he can, goes to church five, six, seven days a week,” Santos said. “He goes every single day and he walks himself. He doesn’t have an aide.”

What has both Miguel and investigators confused is the motive behind this brutal attack.

“Everything is still here, even cash was still in his pocket,’ said Santos. “Everything is still here, credit cards.”

Police say the attacker didn’t say a word before knocking Hernandez unconscious, leaving him in the street. He then fled eastbound on Fox Street.

Residents in the area were sickened by news of the attack.

“It’s the youth today, you know, and it’s unfortunate that these things is happening,” one man told 1010 WINS’ Glenn Schuck. “That’s what they do. They prey on the defenseless.”

The suspect is described as a Hispanic man in his 30s, about 5’9″ and 260 pounds. He was wearing a blue baseball cap, a multi-colored sweater, blue jeans and yellow work boots.

Anyone with information is asked to call the Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782), visit www.nypdcrimestoppers.com or text tips to 274637 (CRIMES) then enter TIP577.