This story contains details some readers may find upsetting.
"I thought my little brother was inside so I came and tried to break the window to help people to exit, and after that I went in."
The 18-year-old man, who did not want to give his name, was speaking to the BBC after a huge fire at a New Year's Eve party in the Swiss resort of Crans-Montana rapidly turned what was an evening of celebration into a nightmare.
Police say dozens of people are presumed to have died when the blaze broke out in a bar called Le Constellation at around 01:30 local time (00:30 GMT) on Thursday. Around 100 more were injured, mainly with severe burns.
The eyewitness told the BBC he was close to the bar when he heard a big explosion, followed by a lot of smoke.
