sergeant jasso was 25, and from ershington state. he was killed in a firefight three days ago. charlie d'agata has more on today's attack. >> reporter: u.s. forces have waged fierce battles against the taliban in ghazni for months, a fight that today cost the lives of more american soldiers. a defense official told cbs news a powerful roadside bomb struck a u.s. military convoy early this morning. attack helicopters flew in to support the evacuation of the wounded. ppe bombing happened in an area where u.s. special forces have been working with afghan commandos against the taliban. last month, we joined american soldiers on field in nangarhar province.ttlethe the vehicle blown up in today's attack was one like this, an mrap, mine resistant ambush protected, designed specifically to defend against roadside dembs-- meaning the explosion that struck the convoy today, causing so many casualties, must