Updated: 24/04/12 : 08:35:03
The charity, Samaritans has said it is "overwhelmed" after receiving over £217,000 in donations in 24 hours following the death of a London Marathon runner.
Claire Squires collapsed in Birdcage Walk near St James's Park while running the final stretch of the 26.2 mile course.
The 30-year-old was collecting sponsorship for the Samaritans because her mother has worked as a volunteer for them for more than 20 years.
Rachel Kirby-Rider, from the charity, said "Obviously we're desperately sad and devastated as an organisation that Claire died whilst running the marathon.
"She was one of 70 runners running for us and our thoughts are with the family at this time and it's really important to us that we continue to support the family during the desperately difficult time for them.
"We're overwhelmed that people are supporting us and the tributes to Claire on her fundraising page and the donations that are coming in in memory of her are amazing.
"We're a charity that doesn't turnover high sums of money so £500, £1,000 is a huge amount of money to us as an organisation."
On Monday tens of thousands of pounds were being donated to the JustGiving site every hour as news of the hairdresser's death spread, increasing the total from just £500 on Sunday.
Tributes also flooded in, with messages left for Ms Squires, from North Kilworth, Leicestershire, on the page and on Twitter.
Close friend Nicola Short paid tribute to Ms Squires, describing her as an "inspiration" who brought laughter and love to everyone's life.
The pair climbed Mount Kilimanjaro for the Royal Air Force Association (Rafa) last year, raising £1,500.
A statement on the London Marathon website said: "The organisers of the Virgin London Marathon would like to express their sincere condolences to the family and friends of the deceased.
"We would like to emphasise that our immediate concern is for the family of the deceased. Our thoughts and deepest sympathies are with them at this difficult time."
Tests to establish why Ms Squires collapsed as she neared the finish line are expected to take place in the coming days.
She died with the finishing line only one bend away, after 25 miles of the marathon.
She is the 11th participant to die since the event began in 1981 and the first woman.