MIAMI BEACH — Rescuers searched Atlantic waters off Florida today for survivors a day after an overloaded boat capsized and sank with about 30 people aboard, mainly Haitian immigrants fleeing their country's crushing poverty.

At least nine people were known to have died, including an infant, U.S. Coast Guard officials said. Sixteen more people were pulled out of rough waters after the first survivors were discovered Wednesday.

The search continued through the night, but the death toll and number of survivors remained unchanged, Coast Guard Petty Officer Nick Ameen said this morning. Crews have used helicopters, cutters, a jet and a handful of small boats to search a combined area of 2,350 square miles.

"A lot of those people were out there treading water for a long time," Ameen said. "Our main goal is everyone's health right now and safety."

Although the Coast Guard hadn't figured out exactly how many people were aboard or how many might still be missing at sea, it appeared most of the passengers were from Haiti and the trip fit the profile of migrant smuggling.

"The boat was obviously overloaded," Coast Guard Capt. James Fitton said. "It's a tragedy that someone would be so callous with human life."