When Bullock is calling over the radio for all eyes to be on the lookout for the Indian Hill bus, a patrol car radios back immediately that it's under the South Burnside Expressway. Bullock replies for him to stop it, after which is a game of chicken and a tommy gun fired at both the patrol car and the bus, ending in a gravity defying multiple vehicle crash. No further radio calls. Four minutes later, he's assembling squads and attack units to all parts of the city to find the bus that he was just told where it was. Even given that "under the expressway" may be a few miles long, none of his search instructions even mention it.