MIAMI BEACH (AP) — The Coast Guard announced Thursday that it found four more bodies while searching for dozens of migrants missing at sea off Florida. However, it would suspend rescue operations at sunset if they don’t have any additional information.

Officials from Homeland Security Investigations said that they were currently investigating the case in an effort to find out if it was a human smuggling operation.

Five bodies have been found by authorities, with 34 still missing. The vessel was on its way to Florida from Bimini in the Bahamas, which is 55 miles (88 km) east of Miami.

Coast Guard Capt. Jo-Ann F. Burdian stated that the decision to suspend the search at sunset on Thursday in the event of any new discoveries was difficult.

She stated that the area was “saturated over and over again” at a news conference. We’ve had good visibility. We have overflowed the vessel several times. … This does not mean that we think anyone else will survive.

The Miami Office of Homeland Security Investigations launched an investigation, stating that the migrants’ journey was part of a human-smuggling operation. Federal law allows a smuggler who is convicted of causing death to be executed.

Anthony Salisbury, HSI Miami Special Agent-in-Charge, stated that “the goal of this investigation was to identify, arrest, and prosecute any criminal organization or criminal group that organized, facilitated, or profited off this doomed enterprise.”

Salisbury refused to provide any details about the nationalities of the passengers on the boat, but stated that investigators consider the sole survivor “a victim now” and not a suspect. Salisbury asked the public to provide information to help identify the organizer of the boat crossing.

He said, “Please help us bring criminals that prey on and victimize vulnerable migrant communities to justice.” “We don’t want anyone doing this again. … This is very dangerous stuff.”

The only survivor was found clinging to the vessel, measuring 25 feet (7 meters) in length, about 40 miles (64 km) from Fort Pierce, Florida. After he and 39 others set out to Florida from Bimini, he told authorities and a good Samaritan that the boat capsized on Saturday.

The boat was located about 100 miles (160 km) north of where it crashed. It was apparently being pushed by the Gulf Stream. This warm and swift current wraps around Florida’s peninsula and runs along the Atlantic Coast of America. According to the rescue man, no one was wearing a life jacket.

Even on a sunny, calm day, the Gulf Stream can prove treacherous. They can be deadly if they are overloaded, have inexperienced sailors, or are subject to stormy weather and dark night.

On Saturday and Sunday, a small craft advisory was issued because a severe cold front with winds of up to 23 mph (33.7 kph), blew through the dangerous passage, creating waves up to 9 feet (3 meter).