President Bush said today that he envisioned a broad emergency alert system to warn the country of biological attacks, calling for an updating of the cold war`s Distant Early Warning system for an age of terrorism. Mr. Bush, pushing his budget requests for sharply increased spending for domestic defense, came here to draw attention to a system developed by the University of Pittsburgh to track, in real time, unusual increases in illnesses, flulike symptoms and other outbreaks of disease at emergency rooms around western Pennsylvania. A version of the system will be used starting later this week in Utah hospitals near the sites of the Winter Olympics, part of the precautions against a terrorist attack at the Games. Full Story