The United States sends letter to ISIS , stressing dam 's strategic importance . ISIS wants to keep Peshmerga working , Congress analyst says . Mosul Dam spokesman : Forces have retaken one side of the dam . Smoke rises from the horizon , and buildings are ablaze in the battle to retake it .
Obama sends letter to Congress , stressing dam 's strategic importance . ISIS wants to keep Mosul Dam working , CNN analyst says . Peshmerga spokesman : Forces have retaken one side of the dam . Smoke rises from the horizon , and buildings are ablaze in the battle to retake it .