Aldon Smith Reportedly Found Unresponsive in Truck, Died in Hospital

New details surrounding Aldon Smith's sudden death are coming to light ... with the reports the former NFL star was found unresponsive inside a truck shortly before he was pronounced dead Saturday.

Smith had spent part of the day with friend Amir Shirazi, helping deliver pizzas to a local homeless outreach organization in the Bay Area before running several errands together, according to the San Francisco Chronicle.

However, after returning to Shirazi's home in Los Gatos, the day took a devastating turn. Shirazi told the Chronicle he briefly went inside the house, only to return and find Smith slumped over in the front passenger seat of a pickup truck.

At first, he reportedly believed Smith was asleep, but quickly realized something was seriously wrong and reportedly called 911 and sought help from former NFL running back Anthony Dixon as they attempted lifesaving measures while waiting for emergency responders to arrive.

Smith was transported to Good Samaritan Hospital in San Jose, where he was later pronounced dead. He was 36 years old.

Authorities have not yet announced an official cause of death. According to the Chronicle, the Santa Clara County Medical Examiner's Office is continuing its investigation, with the cause and manner of death still pending.

In a clip posted the day before his passing, Smith mentions he’s "had better days," but doesn’t go into detail when asked further.

The tragic news stunned the football world, particularly in the Bay Area, where Smith became a star after being selected seventh overall by the San Francisco 49ers in the 2011 NFL Draft.