Charlotte Niddam, a former pupil of a British school, remains missing following the horror New Year’s Eve blaze that killed at least 40 people.
JFS School, a Jewish institution based in Kenton, North London, wrote to children and parents to inform them of the news.
As many as 47 people are said to have died as a result of the blaze, which took place in the early hours of New Year's Day at Le Constellation Bar in the Alpine resort of Crans-Montana.
More than 100 people have also been injured in the fire, with many being treated for severe burns.
Charlotte Niddam had studied at JFS school for two years before returning to France and is among those whose fate remains unknown after the tragedy.
The school letter read: "Following the news of the tragic fire in Crans-Montana, Switzerland, I am writing to ask for your love and prayers in support of Charlotte Niddam and her family.
"Charlotte’s situation, along with many others, remains unknown and the family are awaiting further news.
"Charlotte was a student at JFS for two years before returning to France. She is loved by so many within JFS and is friends with many in our community.
A former British school pupil is among those missing following the nightclub fire in Switzerland
|GETTY
"The family have asked for us to pray for Charlotte and there is a community group where you can, continuing from the previous chapter, recite Tehillim in either Hebrew or English.
"I know that this news will come as a personal shock to many and should your children require any support whatsoever then please do ask them to approach any member of staff so that we help to take care of them.
"Thank you for your compassion and our deepest thoughts are with the family at this time."
Swiss President Guy Parmelin called the fire at Crans-Montana "one of the worst tragedies our country has ever experienced".
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Scenes of the blaze outside the bar in Swiss ski town Crans-Montana
| XHe confirmed the majority of victims were young people and that flags would fly at half mast for five days across Switzerland.
President Parmelin told a press conference: "This event took place in a place that is dedicated to life and joy...what an incredible and dreadful contrast."
Valais Canton police commander, Frederic Gisler, told the conference: "Right now, we have around 40 people who have lost their lives and around 100 people who are injured, many of them very seriously."
Images and videos posted on social media showed a ceiling catching fire after a "waiter held up a sparkler in a champagne bottle."
Asked if bottles containing sparklers were used in the bar, Valais Canton Attorney General Beatrice Pilloud said she was not in a position to confirm.
Ms Pilloud said fire safety will be determined by the investigation and it is too early to conclude on the cause.
Italian Journalist Marco Colombo informed GB News that he feared the death toll could rise further as bodies are identified.
"At the moment, they can't identify the dead. So they've counted, unfortunately, 47 bodies.
"There was one this morning, one boy, a professional golf player aged 17, he has been named so far out of the 47.
"As I was researching and preparing my report online, the family was calling for help saying 'this is what he looks like, please let us know if he's in hospital', and then an hour later, we had to report that that was the first body to be identified.
"There are six that are missing, and the six Italians missing are likely to be dead, because clearly the hospital would have replied to the call, it's now more than 36 hours.
"And the 13 people seriously wounded, some of the kids have been reporting that they couldn't even touch their friends because they were completely burned.
"So it's likely that out of these 13 people in critically in hospital, some may increase the very sad and sickening death toll count."
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