. >> chris polne onhe hill for us.hank you.> at the live desk, following breaking news in the uk where police are calling it a major incident. a man andoman are in critical condition after police say they were exposed to some o type unknown at first they thought this couple had perhaps got aholdwe using drugs and got ahold of a contaminated batch of crack cocaine orheroin. now they're not so sure. they were found unconscious o saturday. n done say testing has b to determine what type of substance they've been exposed to. here's the thing. they were apparently poisoned near the town where that former russian spy and his daughter were poisoned back in march. aaron? >> chris, thank you. >>> 4:48 now. right now at reagan national, last minute holiday travelers one of ng and going in the busiest stretches of air travel in years. six of the top ten busiest travel days on record have happened in just this year. most in the last few weeks. the friday before t fourth of july last year was that the top ten. the other thr busie d