An 85-year-old man who was beaten and left bloody on the sidewalk in downtown Los Angeles died in the hospital Monday morning more than a week after the violent attack, the Los Angeles Police Department said.

Dong Yul Lee died Monday morning at 6 a.m. after a 46-year-old man described as a transient was accused of punching him in the face, and stomping his head to the ground, LAPD said.

LaFawn Parker, the accused attacker, was charged with attempted murder with a special enhancement for elder abuse on April 5.

Police said Parker, a transient, approached Lee on April 2 at 7th and Olive streets.

Parker allegedly punched Lee in the face in an unprovoked attack, and walked away. But then police said he turned back and came at Lee again, stomping his head into the ground and beating him unconscious.

A security guard named Waltay Simmons who witnessed the attack said he jumped into action and tackled Parker.

Simmons said he came upon the chaotic scene at 3:30 p.m.

"I heard somebody yell, 'Oh my God!' I turned around and caught the tail end of a guy stomping a senior citizen's head into the ground," Simmons said.

Simmons was working as a security guard for the Whole Foods grocery store when the attack occurred.

"I just yelled at him and ran at him," Simmons said. "He saw me and started running into the Domino's parking lot."

Cellphone video taken by a witness showed a man in a pool of blood on the ground. Police described the attack as unprovoked and did not have details regarding a possible motive.

"I pepper-sprayed him. [It was] a self-defense thing," Simmons said. "He came at me, and the look in his eyes? It was me or him."

Simmons said he also handcuffed the man, and held him until police arrived.

LAPD confirmed Parker was being held on $1 million bail. It was not immediately clear whether Parker has an attorney.

"A guy without his medicine and a victim who was in the wrong place at the wrong time," Simmons said. "I think both of them were victims, really."