Complex sentence: O'Grady landed among a Bosnian-Serb population, he was briefed it to be unfriendly and, within a minute, he secured a 29-pound survival bag, ran, and hid.
Split into simpler sentences: O'Grady landed among a Bosnian-Serb population he was briefed would be unfriendly. He quickly secured a 29-pound survival bag, ran, and hid.