Scientists fear that lethal gas is again filling the Cameroon lake that two years ago spewed a cloud of poison that killed 1,743 people. Felix Tchoua, a vulcanologist at Yaounde University, fears that Lake Nyos is recharging, and as a precaution he advocates close monitoring of Nyos and other lakes. The government sent his expert team to the region after a recent report that nearby Lake Bambuluwe could be about to erupt like Nyos.