All 29 men missing in a New Zealand coal mine have died after a powerful second blast tore through the pit, plunging the country into mourning. Police said there is now no chance of finding anyone alive, confirming the country's worst mining accident in nearly a century. Prime Minister John Key called it a national tragedy and said flags would fly at half-mast.Police Superintendent Gary Knowles, who led stuttering rescue efforts, said he was at the mountainside Pike River mine when the second explosion, five days after Friday's initial blast. The victims of the blasts ranged from a 17-year-old on his first shift to a 62-year-old veteran, and include two Australians, two Britons and a South African. District mayor Tony Kokshoorn said the incident was the darkest hour of New Zealand's rugged West Coast region, a centre of the country's burgeoning mining industry based on exports to Asia. The mine is a new facility that sent its first shipment of hard coking coal for making steel to India only this year.