A sea turtle was stranded on the Oregon Coast.

A pair of endangered sea turtles, rescued in separate incidents after being stranded on the coast last week, died after attempts to rehabilitate the injured animals were unsuccessful.

The first turtle, an olive ridley, was discovered by Oregon state trooper Josh Mullins after he responded to a call from a resident who found the animal on Horsfall Beach, north of Coos Bay.

The animal had been spotted earlier and looked to be free of injury, but search crews were unable to find it before high tide. Experts from the Oregon Coast Aquarium believe the animal may have been washed out to sea and sustained further injuries.

When Mullins found the ailing creature, it had cracks in its shell and was lethargic. By the time the turtle was brought to the aquarium the next day for treatment, its body temperature was roughly 30 degrees colder than normal.

The female turtle was named “Donatello,” after a character in the “Teenage Mutant Ninja Turtles” comics, when social media users saw it dressed in purple bandages.

On Saturday, a couple walking along the beach in Waldport spotted the second turtle, also a female olive ridley, and called the aquarium.The couple enlisted the help of state parks ranger Doug Sestrich to carry the animal to safety before it, too, could be brought to the aquarium for rehabilitation.

Winter months can often prove perilous for sea turtles off the coast of the Pacific Northwest. Sometimes blown off course by strong storms, the creatures can end up in water much too cold for them and strandings are not uncommon along Oregon beaches.

Initially, experts at the facility were hopeful but guarded about both sea turtles’ conditions. Donatello was responsive to her handlers and blood work showed no signs of infection. Subsequent analysis showed that her kidneys were severely compromised. The second turtle was suffering from cold-stun, said Evonne Mochon-Collura, Oregon Coast Aquarium curator of fish and invertebrates.

“While she appeared physically intact, cold-stunning itself takes its toll on the turtle’s internal organs,” Mochon-Collura said in a statement. “As always with animals with sustained injuries, they have a lot of challenges through recovery. We submitted X-rays and blood samples for further analysis to determine her internal condition.”

Both animals died Sunday, the aquarium reported.

The odds of rehabilitating stranded sea turtles are low, but the aquarium has had success in the past, specifically with two turtles named “Lightning” and “Solstice,” both found on Oregon beaches and tended to at the aquarium. After being released in 2017, their movements were tracked in known breeding grounds off the coast of Mexico this spring.