<p><br /> Rescuers have begun drilling an escape shaft to save 33 miners trapped after a cave-in at Chile's San Jose gold and copper mine.<br /> </p><p><br /> The bid to rescue the miners, stuck in a hot and humid tunnel half a mile underground, could take between two and four months. The government has turned to Nasa and submarine experts for help.<br /> </p><p><br /> Striving to keep the men physically and mentally fit for the wait ahead, doctors sent flu vaccinations and nicotine gum for smokers in withdrawal down a tiny shaft the size of a grapefruit, the men's umbilical cord to the outside world.<br /> </p><p><br /> Rescuers started drilling a 2ft-diameter shaft on Monday evening that will be used to evacuate the miners one at a time in a cage attached to a pulley.<br /> </p><p><br /> Engineers are also looking into other options to speed up the rescue, including digging a second escape duct that could take about 60 days.<br /> </p>
