THE UNITED STATES is evacuating all U.S. dependents and non-essential staff from Somalia due to a rise in factional fighting, armed robberies and shootings that have claimed at least 30 lives in the capital . . . SIR IAN TRETHOWAN, the chairman of Thames Television and a former director-general of the British Broadcasting Corp., died at age 68 in London a few hours after Thames said he was retiring because of ill health . . . A POLAR BEAR that killed a man in an Alaska village over the weekend was starving, scientists said Wednesday, giving rise to worries that more hungry bears could be prowling the arctic coast. No fatty tissue was found on the bear, which was tracked down and shot after it attacked and ate a man who had been walking through the village with a female companion.