“Goodbyes are bittersweet, but it’s not the end. I’ll see your face again.”

This One Direction lyric, about losing somebody, has been repurposed as a tribute – scrawled on notes and stuck to trees, outside the hotel in Buenos Aires where Liam Payne fell to his death from a balcony on Wednesday.

Crowds of people have been gathering here since news of the tragedy broke – some in tears, some singing One Direction songs as they light candles and leave flowers.

It’s a reminder of just how huge Payne’s former band were internationally. One Direction’s global tour in 2014 kicked off in South America, attracting millions of fans, with two shows in this city.

The sombre mood outside the CasaSur Hotel reflects the grim nature of the news that has been emerging over the last 24 hours.

On Wednesday evening, local emergency services were called by the hotel’s staff concerned about a guest who was “aggressive” and under the influence of drugs and alcohol. They feared his life was in danger because of his room’s balcony.

A harrowing 911 call, obtained by local newspaper La Nacion, reveals staff imploring the operator to “send someone urgently”.

There are some big questions here about how this call, along with some initial photographs purporting to show scenes of the aftermath, spread on social media and leaked to some news outlets, while the news of Payne’s death would have still been reaching some of his loved ones.

The singer had fallen from his balcony after officers arrived at the scene, with the officer in charge saying he heard a loud noise after arriving. He was rushed to hospital, but his injuries were too severe for him to be resuscitated.

An initial post-mortem investigation suggests Payne died from internal and external bleeding. Police in Argentina say inspections were carried out of the area where he died on the ground floor, where a bottle of whiskey, a lighter and a mobile phone were found.

In his hotel room, a state of “total disorder” was found – including things broken and multiple packets of medication including the anti-anxiety medication Clonazepam.

Evidence is being gathered here and taken to a laboratory, while Payne’s body has been taken to a morgue, in the hope this may provide further answers.

Police are waiting for family to officially confirm the identity of his body. It’s not clear yet when he may be repatriated to the UK.

One guest at the hotel, Doug Jones, told the BBC he was working in the building on Wednesday when he heard loud noises and banging coming from a room, and saw staff entering and leaving it.

He assumed the hotel was “doing work” on the room, before he heard a “loud, violent scream”.

Mr Jones said it was his first time visiting a country outside the US, so did not know if this was “normal”, until he saw the road filling up with emergency vehicles and knew something was wrong.

For his fans, news of Payne’s death came as a shock as they had recently seen videos of him on social media seemingly having a nice time in Argentina – spending time with his girlfriend Kate Cassidy and attending a concert of his former band mate Niall Horan.

“We were very confused, because of the Snapchats,” said 29-year-old Magali Dalmau, a fan who came to the hotel to pay tribute to the star.

She said she started listening to One Direction when she was aged about 13.

“We all just bonded with them. It means the death of our teenage years. We’ve lost hope of the five of them having a reunion. It’s really sad. The way it happened is the saddest part.”

Shooting to fame at just 16 years old, and dying at 31, many of his fans were a similar generation and grew up with him.

A 21-year-old Brit, Ivor Radway, who lives around the corner from the hotel told the BBC he had seen One Direction at Wembley and the news had “really shocked” him – leaving him wondering if Payne had received enough support.

Indeed, many fans remember him as a smiley singer of feel-good tunes – a far cry from the horrifically dark image painted of his final moments.

But it wasn’t a secret he’d faced demons. He’d spoken openly about struggling with alcohol, mental health problems and the struggles of fame and of parenting a young son at times.

The BBC had also seen a cease-and-desist letter against the singer earlier this week from his former fiancée, the model Maya Henry.

She’d accused him of repeated unwanted contact, but he’d not responded to the allegations.

His music, and openness about his own mental health, were what drew some fans to him.

One tribute left outside the hotel reads: “Thank you for saving my life. I’m sorry I couldn’t do the same for yours.”