ORLANDO, Fla. -- A Carnival cruise ship passenger from Orlando died over the weekend while tubing through caves in Belize.

The 52-year-old nurse was reportedly healthy. She had even run a marathon recently, but the river was too much. Witnesses said the river she was tubing down was too full, the current was too strong, and that no one should have been in it in the first place.

Witnesses also said a strong current forced Linda Linan and her husband Eduardo, to hit a cave wall and flip over. They were taking part in a ship-organized activity called dark cave tubing.

An eyewitness who didn't want to be identified said he heard people screaming and just narrowly missed colliding with them himself.

"The river basically dead ended straight into a wall. The current was pushing people against a wall and tubes were going on top of people," said the eyewitness.

Guests of the Carnival Glory cruise ship could only hear screams ahead.

“The guide just started screaming and yelling. There was a lot of yelling going on. Turn right, turn right, " the witness said.

Another tourist pulled Eduardo from the water, but Linda drowned. Witnesses said a nurse and a police officer along for the tour eventually performed CPR, but she never revived.

In a statement issued Sunday, Carnival Cruise Lines said it has suspended all future sales of the cave tubing excursion and has launched an investigation into what happened.