bridge collapses. sending a tourist bus plunging into the forest below and the death toll could get higher. clock is ticking and tensions are soaring and if you want an idea how things heat are over the debt crisis, listen to this. president obama storms out of yesterday s meeting vowing he will veto any extension of the debt ceiling that is only short term. reports say he said to aeric cantor, quote, many could bring down my presidency. the august 2nd deadline is looming and pessimism is growing. a major rating agency says it will review the nation sterling bond rating for a possible downgrade. we are covering the angles of this all-important debt talk story. dan lothian at the white house with reaction to the extraordinary ratcheting up of tensions. ali velshi is giving us the bottom line on the economics. why should you care that u.s. bonds could face a brutal reality check? ali, let s start with you. a downgrade would be like seeing your personal credit score take a