registered for international transport, and the operating firm s license will be revoektded. north macedonia and bulgaria have declared national days of mourning in memory of the victims. phil black has our report. reporter: the long highway winding through bulgaria s countryside is now quiet. at least 45 people, including 12 children, were killed here early tuesday morning after this bus caught fire. flames quickly overwhelmed almost everyone onboard. it s hard to look, hard to look. i don t know if we should go into the details at this early hour. let s leave it for a later hour. in my experience, i ve never seen anything like this. people are clustered inside. they are burned to ash. reporter: just seven people sitting near the back survived by smashing windows to escape.