It occurred in the city it was named after, Marburg Germany. Caused by infections from monkeys, the virus soon got a hold of the Human race and, through rapid succession, killed 7 of 31 people who had gotten infected with the virus.
Charles Monet arrives at Nairobi Hospital because he has been infected with the Marburg virus and his body is deteriorating quickly. He suddenly collapsed in the waiting room and starts bleeding profusely. Dr. Musoke, who treated Monet, is infected by Monet's blood and Monet dies, but Musoke lives.