(NewsNation Now) —  U.S. Border Patrol said that a large group of possibly 70 people tried to illegally cross into the United States by swimming around a barrier in the ocean from Mexico.

They entered the water in Tijuana and then tried to swim north, attempting to reach Border Field State Park in San Diego, according to a statement.

Most of them didn’t make it, however. Border Patrol agents took 36 people into custody and one woman died after struggling in the water.

Responding agents found an unresponsive woman believed to be from the group and attempted CPR, officials said. She was declared dead at about 12:30 a.m. 

Multiple agencies worked together to gather the migrants, including the U.S. Coast Guard, which rescued 13 of the 36 people who were taken into custody.

The Border Patrol called this border-crossing attempt a “ruthless smuggling tactic” by organizations that charge a fee to get people illegally into America.

During September, the total number of unique encounters between internationals and border patrol agents was down 9%.

The total number of unaccompanied children decreased by 24%.

And for entire families trying to cross into America, that number is down 26%.

While those numbers for the month of September have been down, the Biden administration has been struggling to manage the surging number of migrants that are entering the U.S. since the pandemic began.

The Associated Press contributed to this report.