'This is not how sequoias die. It’s supposed to stand for another 500 years'

Giant sequoias were thought to be immune to insects, drought and wildfires. Then the unthinkable happened: trees started to die - and scientists began the search for answers

• Beetles and fire kill dozens of 'indestructible' giant sequoia trees

Photographs by Mette Lampcov

The fable of the giant sequoia tree is an enduring tale of America's fortitude. Standing quietly on the western slopes of the Sierra Nevada, the Californian giants can survive almost anything - fire, disease, insect attack, cold years, hot years, drought - so the story goes.

The largest living organisms on the planet can grow over 90 metres (300ft) tall. When they do die after 3,000 years or so, the oldest trees, known as monarchs, usually succumb to their own size and collapse. Their giant trunks will rest on the forest floor for another millennia.