With Hurricane Ike steaming into the Gulf of Mexico, Texas emergency officials Tuesday stood ready to order 1 million people evacuated from the impoverished Rio Grande Valley and tried to convince tens of thousands of illegal immigrants that they have less to fear from the Border Patrol than from the storm.

Video: Ike Hits Cuba | Track Ike

Emergency planning officials were meeting all day to decide if and when to announce a mandatory evacuation for coastal counties close to the Mexican border.

With forecasts showing Ike blowing ashore this weekend, authorities lined up nearly 1,000 buses in case they are needed to move out the many poor and elderly people who have no cars.

Federal authorities gave assurances they would not check people's immigration status at evacuation loading zones or inland checkpoints. But residents were skeptical, and there were worries that many illegal immigrants would refuse to board buses and go to shelters for fear of getting arrested and deported.

One reason for the skepticism came in May. Homeland Security Secretary Michael Chertoff said the Border Patrol would do nothing to impede an evacuation in the event of a hurricane. But when Hurricane Dolly struck the Rio Grande Valley in late July, no mandatory evacuation was ordered. The Border Patrol kept its checkpoints open and agents caught a vanload of illegal immigrants.

Mexican officials said more than a dozen dams in the northern state of Chihuahua were at capacity or spilling over, heightening fears of flooding on the American side of the border.

The Dallas-Fort Worth area sheltered about 3,000 Hurricane Gustav evacuees last week and is prepared for up to about 20,000 people this time. The downtown Dallas Convention Center would again serve as the main shelter.

4 Killed in Cuba, Millions Evacuated

Hurricane Ike roared across Cuba west of the densely populated capital's aging buildings Tuesday after tearing down the length of the island nation, ravaging homes, killing at least four people and forcing 1.2 million to evacuate.

Winds howled and heavy rains fell across Havana, where streets were empty. Towering waves broke over the graceful Malecon seaside promenade, which police had barricaded off the previous evening. Many of the historic apartment buildings along its length are in poor repair and vulnerable to collapse.

Police spread out across the city to halt all but emergency and official traffic. Roadways were strewn with tree branches and rocks, and the rubble from crumbling balconies littered sidewalks. Navigation was banned in Havana Bay, its usually placid surface stirred up by white-capped waves.

State television reported that Ike killed four people in Cuba -- the island's first storm deaths this year. Two men were killed removing an antenna from a roof, a woman died when her home collapsed and a man was killed by a falling tree.

No one was killed when Gustav tore across western Cuba -- the same area Ike was pounding Tuesday -- as a monstrous Category 4 hurricane on Aug. 30, damaging 100,000 homes and causing billions of dollars in damage. That was largely because 250,000 people were evacuated.

At 8 p.m. EDT, Ike was about 95 miles west of Havana, Cuba, moving west-northwest at 10 mph with sustained winds near 75 mph. It was expected to cross the Gulf of Mexico, strengthening to a Category 3 with winds of up to 130 mph.