An 83-year-old man has died from injuries sustained after being pushed onto subway tracks in Manhattan last weekend, prompting authorities to upgrade charges against his alleged assailant to murder.

The victim has been identified as Richard Williams, a retired Air Force veteran. Williams was reportedly pushed onto the tracks in what appears to have been a random attack.

Following Williams' death from his injuries, the suspect now faces murder charges in connection with the incident. The case has drawn attention as another example of violent crime in the city's subway system.

According to the Department of Homeland Security, the alleged assailant is an undocumented immigrant. The suspect was initially charged with lesser offenses before the charges were elevated following Williams' death.

The incident occurred during the weekend in Manhattan's subway system. Police have not released additional details about the circumstances surrounding the attack or the current condition of the suspect in custody.

The death adds to ongoing concerns about safety in New York City's transit system, where officials have been working to address various security challenges.