At 4:53:09 pm on 12 January, at a point 25 km southwest of the Haitian capital Port-au-Prince, the Caribbean Tectonic Plate pushed against the neighbouring North American plate and caused one of the worst-ever natural disasters. An already desperately poor country was left in ruins. 

On Saturday 20 February the beautiful island of Madeira was confronted by huge floods. The island's capital Funchal has been devastated. 

On that same Saturday Chile was hit by an 8.8 magnitude earthquake, the seventh most powerful on record and the worst disaster to befall Chile in 50 years. The wine industry has been badly affected, with many producers having already started to harvest grapes. 

Médecins Sans Frontières (MSF) is an independent humanitarian medical aid organisation. It delivers emergency aid in more than 60 countries to people affected by armed conflict, epidemics, natural or man-made disasters or exclusion from healthcare. 

MSF is entirely independent and relies on donations to support its work. Private funding gives MSF the freedom to respond to the greatest needs as fast as possible without political interference. 

I have a close friend who works for MSF and she was recently in Haiti. Although she would not be drawn on what she saw it was obvious that it had affected her deeply. 

On Saturday 6 March we will be walking across eight London bridges, from Tower Bridge to Westminster Bridge, to raise money for Médecins Sans Frontières and its work in Haiti, Madeira and Chile.  

Tragedy has a way of visiting those who can bear it least. Please give generously and ask friends, family and colleagues to sponsor us – or even walk with us. 

Stuart George and Val Blakely