GREYMOUTH, New Zealand: All 29 miners trapped underground in a New Zealand mine for five days are believed to be dead following a second explosion, police said on Wednesday, as the government vowed to investigate the disaster. The miners were trapped in the 2.3 km main tunnel of the Pike River Coal mine last Friday night when methane gas caused a massive explosion in the mountain on New Zealand's south island. Two other miners narrowly escaped by running out of the mine. “Today all New Zealanders grieve for these men. We are a nation in mourning,” said Prime Minister John Key in an address to the nation in which he announced an inquiry would be held into the disaster. Deadly toxic gas and fears of further explosions stopped rescuers entering the mine, despite desperate pleas by the miners' relatives that rescue teams enter the mine to find their husbands and sons, aged between 17 and 62. Distraught relatives of the dead miners were angry that rescuers had not immediately entered the mine to save their loved ones.