Mine Explosion in New Zealand

On Friday, November 19, 2010, workers were trapped after a mine explosion in New Zealand. A robot was dispatched, but it broke down before reaching the men.

(CNN) A second robot has arrived at the site of a coal mine in New Zealand where an explosion trapped 29 workers underground, police said.

But police officials stressed that it remained too dangerous for human rescuers to go underground, and the situation at the mine was growing increasingly grim with each passing hour.

“The situation is bleak. It is grave. And you have to understand that the risk posed by a secondary explosion is real,” Gary Knowles, superintendent of the Tasman Police District, told reporters Tuesday.