A Southern California couple tried to save a swimmer killed in a crocodile attack while they were on family vacation in Mexico.

Chris Bury and his fiance Jamie Yetter were at their hotel pool in Puerto Vallarta when they heard screams from the nearby beach at around 7 p.m. Friday.

Thinking the victim was caught in a rip current, they rushed to help only to see the deadly attack unfold in front of them off Marina Vallarta Beach.

“The crocodile had him by the thigh,” Yetter told ABC7. “The size of this crocodile, I mean, his head was as long as my torso, his tail thicker than my legs. He was just turning him, taking him under.”

The San Clemente couple, on holiday with Yetter’s teen daughter to celebrate her high school graduation, described the scene as “pretty traumatizing”.

Bury initially tried to throw the swimmer — later identified as a 28-year-old local man named Irving — a life preserver but he was unable to grab on to it.

“I was in the water up to my waist, he was maybe 20 feet away… he was in shock and flailing” Bury told CBS News LA.

“I hopped in [a] kayak. By the time it got to him, it had drug him under and then that was it. He was gone after that.”

The victim’s body was found 12 hours later, following an extensive search by the Mexican Navy, lifeguards and other authorities, Jalisco Police told NBCLA.

Footage taken from the scene and shared by local outlet Noticias Puerto Vallarta shows the crocodile in the surf before it was captured by authorities.

Yetter told CBS News LA that the morning after the fatal attack the beach was still open and she could not see a ‘no swimming’ sign.

Diego Thomas, a spokesperson for the nearby hotel Marriott Puerto Vallarta where the couple stayed, told The Independent: “We extend our thoughts to the individual and their loved ones during this difficult time and are providing appropriate support in line with our policies,.

“The safety and security of our guests and associates are our top priority.”

Thomas added that they have “appropriate signage, as well as night patrolling and red flags to indicate caution in the area and all were and are properly in place.”

The Jalisco State Civil Protection and Fire Department described the fatal attack as an “extremely unusual event”, CBS News LA reported.

Although Puerto Vallarta is built alongside a crocodile habitat, official statistics say that fatalities are vanishingly rare, recording one death per 2.5 million people.

A Jalisco government spokesperson said the start of the rainy season in late June had increased water levels and allowed reptiles to move to areas close to beaches, Jalisco Noticas reported.

In the aftermath of the incident the government has increased surveillance in the area and reminded visitors to avoid locations where crocodiles have been reported, local outlets added.