Search patterns include movement against room walls (to prevent rescuers from becoming lost or disoriented) and methodical searches of specific areas by designated teams.

Thick smoke and dangerous levels of carbon monoxide prevented rescuers from reaching trapped men.

Doctors, nurses and patients at Charity Hospital had to plead for help for more than 100 patients, who were later evacuated after violence had earlier prevented rescuers from getting in.

But a Navy spokesman, Gerry Malabanan, told Agence France-Presse that large waves and heavy rain had prevented rescuers from reaching some survivors.

The explosion early Monday trapped the 13 miners more than two miles inside the mountainside, releasing toxic carbon monoxide that prevented rescuers from reaching them for more than 40 hours.

The blast, which happened at the Dulka mine at Dolná Súča, Slovakia, caused an underground fire that prevented rescuers from reaching the trapped men.

Fires prevented rescuers from reaching the heart of the scene.

He said the strategy was being tried because carbon monoxide and methane gas were preventing rescuers from venturing inside.

But the opinion was general that his body had been cremated in the hot flames that had prevented rescuers from searching the automobile.

Instead he raised his voice in the call of distress common to his tribe, adding to it the warning which would prevent would-be rescuers from running into the clutches of Sabor.