A Long Beach lifeguard and a Good Samaritan, identified by a witness as Cullen Lethin, saved a large black Labrador that was on the brink of drowning off Granada Beach Saturday.

The incident, at the site of Rosie’s Dog Beach, happened around 2:30 p.m. Saturday when a panicked crowd called the attention of lifeguard Ariel Burns. They told her a dog had charged into the water and had swam out to sea, Gonzalo Medina, Marine Safety chief, said.

Lethin saw the situation and dived in to help, followed by Burns, according to the witness. The two swam about 150 yards to catch up to the dog that seemed determined to get to one of the offshore oil islands, Medina said.

Medina said the two rescuers and the dog seemed physically exhausted from treading water. At one point, Burns handed Lethin her floating device, the rescue can, and the dog was seen falling lower into the water, Medina said.

When they finally reached the dog, Medina said Burns swam under water beneath the heavy dog in an effort to keep its head above water as they made the journey back to shore. Things seemed dire, but Medina said the three returned to shore just in time, and the dog was safely returned to the owner.

“I’m extremely proud of lifeguard Burns,” Medina said. “She was shaken up when she got back to shore because the dog was so heavy, and for a moment halfway back, she wondered if she could keep it above water. However, she remained poised, relied on her training and rescued the dog.”

This story has been updated to include the witness’ account and the identity of the Good Samaritan.