Mayor Ray Nagin unveiled a new evacuation strategy for New Orleans on Tuesday that relies more on buses and trains and eliminates the Superdome and Convention Center as shelters. The mayor, facing a runoff election May 20, has been widely criticized for failing to get the city's most vulnerable residents out of town as Hurricane Katrina approached. The new plan also touches on a heart-wrenching decision evacuees faced ahead of Katrina: To board the buses, they had to leave their pets, and some refused to go without them. In the future, evacuees will be allowed to bring pets with them as long as they have some type of cage to safely put them in.