Hopes are fading for the safety of six miners trapped in a mine in Utah as rescuers close in on their suspected location.
A tiny microphone lowered deep into the earth today has picked up no evidence that six coal miners caught in a cave-in four days ago are still alive.
However, an air sample indicated there was enough oxygen to breathe in the chamber where the miners were trapped.
Using a steel drill bit to bore a two-and-a-half-inch wide hole more than 1,800 feet into the mountain, rescuers finally broke through late yesterday into the cavity where authorities believe the miners are trapped.
A crude measurement found enough oxygen to keep the men going if they survived the collapse. Though the air sample indicated plenty of oxygen and no methane in the pocket, it did not pick up carbon dioxide, the gas exhaled when people breathe.
Drilling is continuing on a second, wider hole that could accommodate a powerful camera to provide a view inside the pocket and deliver food and water.
Work also continued in the mine, where rescuers were slowly burrowing through the debris to reach the workers.
AP