Mahial Sran, 20, a San Jose State University student, and Harshita Nair, who attended UC Berkeley, were pulled into the water along the coast, officials said.
"We put eight rescue swimmers in the water, and we had a number of people up on the banks observing and helping to point out where the people were and assist with efforts," said Santa Cruz County Fire Capt. Kyle Breton.
Rescue swimmers brought both Sran and Nair to shore, but both later died, officials said.
MORE: Man missing after being swept into ocean off Big Sur coast ID'd as US Army specialist
Early reports suggested the two may have been sleeping along the beach when they were pulled into the water, but a witness told authorities that was not the case. Sran's father said Monday night that his daughter's bag and phone never got wet, leading him to believe they were near the water and then struck by a wave.
Breton said changing tide conditions in the area may have contributed to the incident.
"So the tide had definitely come in, and one of the problems here is that. Panther and Yellow Bank Beach are separated by what we call the keyhole. And as soon as the tide comes in or gets high, the keyhole is inaccessible. And so, what happens is people go through the keyhole, thinking they're gonna have a great day at the beach, and then all of a sudden, they get cut off, and options run out very, very quickly. And so that's sort of what happened that day," Breton said.
He added that a sneaker wave may have been responsible.
MORE: Man and child hospitalized after water rescue at San Mateo Co. beach, officials say
UC Berkeley Student Body President Abigail Verino said Nair was deeply committed to helping others, including through her internship work focused on marginalized communities of color.
"She was such an incredible person, and she always made the effort to show up, and I would say she is someone that embodies what it means to be part of a community larger than yourself," Verino said.
Authorities urged caution along the coast, noting that a Beach Hazard Statement remains in effect.
"Within a one-mile stretch of beach here, we've run five rescues in the past month. And comparatively, we run about six to eight ocean rescues a year along this section of beach," Breton said.