New Delhi, Oct. 9 -- Sometime in the afternoon on September 29, the Lilagar river, usually a calm tributary of the Mahanadi but at the time in spate for days following heavy rains, changed course and broke through an embankment to flood a Coal India mine in Chhattisgarh's Dipka. It inundated open pits, submerging heavy machinery, and knocking out operations that may take weeks to normalise....