(CNN) -- Rescuers in New Zealand were testing a high-tech robot Monday that they hope will provide key information in their search for 29 miners trapped underground.
A toxic mix of gases inside the coal mine still made it too risky for humans to enter Monday night, officials said. But the robot could enter "in the reasonably near future," Pike River Coal CEO Peter Whittall told reporters.
No one has heard from the men -- ages 17 to 62 -- since an explosion inside the mine around 4 p.m. Friday. Officials hope they are alive, though they do not know if the men found a haven or whether parts or all of the mine collapsed.
"We still remain optimistic. We're still keeping an open mind, but we are planning for all outcomes. ... We're planning for the possible loss of life as a result of what's occurred underground," said Gary Knowles, superintendent of the Tasman Police District.
CNN
