an elephant used to trans-port tourists in the central highlands of vietnam has died of overwork,local media reported yesterday.the40-year-old male asian elephant col-lapsed on sunday in dak lak province while carrying tourists on sightsee-ing trips,newspaper viet nam news reported.only around 50 tamed elephants remain in the province .the animals are not breeding because of overwork and a lack of natural envi-ronment caused by shrinking forests,newspaper tuoi tre report.dpa