The 110-year-old Mahabodhi tree, under which Buddha attained enlightenment 2,600 years ago, is being attacked by "a debilitating disease" every monsoon, giving the Mahabodhi society and Unesco, who declared the Mahabodhi Temple a world heritage site on June 27 this year, sleepless nights. The tree, which is the fourth descendant of the original tree, having grown from the branch of the original tree, is one of the chief attractions for millions of pilgrims who take a symbolic walk around it as a part of their prayer. Not wanting to take any chances, Unesco has written to the Centre for Science and Environment, the Bihar tourism department, the Mahabodhi Society and Indian Tourism Development Corporation to find a permanent solution to this problem, which threatens to wipe away the tree for good.