Is there an absence of a logical link between 'Beginning at 8:52, the controller made repeated attempts to reach the crew of United 175.' and 'The controller cared about the crew of United 175, so he tried to contact them several times.'
Beginning at 8:52, the controller made repeated attempts to reach the crew of United 175.###The controller cared about the crew of United 175, so he tried to contact them several times.