ET breaks down everything to know about Liam Payne's death investigation, from the drugs reportedly found in his system, to the singer's final hours at his Buenas Aires hotel. A week after he died from a 45-ft. fall, ET also looks at how his loved ones and One Direction bandmates are paying tribute. This comes as an eyewitness tells ET, 'Liam had been physically aggressive to people in the elevators and was acting erratically in the hotel lobby... At around 4:54 p.m., Liam passed out in the lobby and looked as if he was twitching. Three hotel staffers came around him and tried to help him regain consciousness and get him out of the lobby.'