Two coaches of the Doon Express today caught fire in the wee hours today near Giridih district in Jharkhand. Seven people have reportedly been killed in the incident. The fire broke out in the AC 3-tier coaches, B1 and B2, when the train was passing through Nimiaghat station in the district, Divisional Railway Manager (Dhanbad Division) Sudhir Kumar said. It was on its way from Howrah to Dehradun.