Stunned guests at the hotel’s SkyLounge on the 12th floor were quickly ushered away by concerned staff as the area was quickly sealed off.
Balazs Szeljak, 35, who works at the Cheshire Cheese pub a few yards from the hotel said a man had sprinted into the bar and told people someone had fallen.
‘Some people were screaming,’ he told the Evening Standard. ‘He said he couldn’t help him, there was nothing he could do as he was in such a bad way.’
Mr Szeljak said police had cordoned off the section of the pavement where the man had landed. It is thought this was outside the executive lounge at the back of the hotel.
Staff and customers at other restaurants and pubs nearby were ordered inside as emergency services arrived at the scene.
One City investment broker who had been drinking at the SkyLounge said: ‘We were outside on the rooftop bar in a private area when suddenly all these police came up.
‘The staff told us they had to cordon off the area. It was pretty packed we were all ushered inside. We didn’t know what was going on.’
A spokesman for City of London Police said emergency services were called at around 4.50pm.
She said he was in a serious condition and pronounced dead shortly afterwards.
A spokesman for DoubleTree by Hilton Tower of London said: ‘It is with deep regret that we can confirm the death of a man at the hotel yesterday evening.
‘Team Members acted swiftly to alert the authorities and the police and ambulance services were onsite shortly after the incident occurred.
‘The police have since confirmed that the death is not being treated suspiciously.
‘Safety and security at the hotel are of paramount importance and we continue to make every effort to ensure that all practises are in line with our strict safety and security procedures.’