isis terrorists going door to door in one ancient city hunting down soldiers. this as we get word that they re now controlling 50% of syria. half of syria. president obama responding. what is he saying? also one of those bikers arrested in that deadly shootout on sunday is now walking out of jail. hear why. and david letterman s run on the late show is now officially over. he went out in the a star-studded finale last night. coming up we re talking to the science teacher behind the popular kid scientist segment. stay with me. 40% of the streetlights in detroit, at one point, did not work. you had some blocks and you had major thoroughfares and corridors that were just totally pitch black. those things had to change.