Some people walking along the water in Ocean Beach made a grisly discovery on Monday morning.
The body of a fully-clothed man believed to be Latino had washed ashore, according to a spokesman for the city of San Diego.
The man had no obvious signs of trauma, according to San Diego public information officer Jose Ysea, who told NBC 7 that the man's death is believed to be related to a human-smuggling attempt on Saturday night in which three people were rescued and at least one other person died. A full investigation will need to be undertaken to confirm that connection, Ysea said.
The panga boat the immigrants were believed to have been in capsized near the Ocean Beach Pier in what authorities believe to be the fifth human smuggling attempt detected in San Diego in a week.
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Witnesses called lifeguards at about 10 p.m. Saturday to report there were people on a boat who were screaming and asking for help and saying, "no police," the San Diego Police Department said.
The boat, with a number of unknown people on board, capsized at around midnight during high surf that was producing at least 8-foot waves, SDFD Lifeguard Lt. Rick Stell said.
Four to five people were believed to have been able to make it ashore and ran away. Once lifeguards arrived, three people had to be rescued and a fourth person was found deceased an hour later, authorities said.
On Monday, the Consulate General of Mexico in San Diego said the man who died was a 37-year-old Mexican national who was a native of the state of Guerrero.
Although the Border Patrol eventually arrived, no arrests were made.
U.S. Customs and Border Protection believed it was an attempt to illegally cross into the U.S.
"At this time, all indications are that this was an attempt to enter the U.S. illegally at sea, but CBP does not have any additional information regarding the nationalities or other information regarding the individuals involved," the agency said in a statement.
A second boat was stopped hours later, according to CBP. At around 3 a.m. on Sunday, CBP Air and Marine Operations intercepted a boat with 15 people on board near Point Loma. CBP said 15 people on board were attempting to enter the U.S. illegally and were detained.
On Monday, three separate panga boats carrying 72 migrants were also spotted in Point Loma, CBP said. All were taken into custody and taken to nearby Border Patrol stations to be processed.
"We have seen that smugglers are bringing in larger groups and putting them in more remote and dangerous areas," Alfonso Martinez, deputy chief of the Border Patrol in San Diego.