As the search for the missing Titanic tour submersible and its five passengers continues, the dangers of venturing 13,000 feet down to the ocean floor to see the wreckage of the infamous sunken ship are coming to light. A former ABC News science editor knows them all too well after a voyage to the wreckage more than 20 years ago went awry.
In September 2000, Michael Guillen, a trained physicist and then-science editor for ABC News, was invited on an expedition run by a group of Russians to be the first journalist in history to make the journey to report at the wreckage site in the North Atlantic Ocean.
Despite Guillen's deep fear of water, he felt he could not turn down the monumental assignment, he told ABC News on Tuesday.
After setting sail from Halifax, Nova Scotia, the crew traveled about 2.5 miles to the sunken ship -- about a 2.5-hour expedition -- when "something happened," Guillen said.
The submersible started the tour at the bow of the ship, making its way to the stern, toward the propeller that had broken into two pieces when the ship sank in April 1912. As Guillen admired the contrast between the shiny brass propeller and the gray, crumbling ruins surrounding it, the submersible got caught in a high-speed underwater current and slammed right into the propeller blades, he said.
"At first, we sensed the collision," Guillen said. "There was no doubt about it."
Guillen was in shock and disbelief as he lay on his stomach in the claustrophobic submersible, witnessing through the porthole giant rusted pieces of the Titanic fall on their vessel.
The entire crew immediately knew the kind of peril they were in and fell silent. Guillen said they could see that the pilot was "at the edge of his seat" and kept quiet for the better part of an hour so as not to distract him.
Immediately after the crash, his scientific mind went into overdrive to try to find a solution -- a way out.
While there was another submersible in the region, Guillen knew that the likelihood of that vessel being able to pull them out was very low, especially given the hostile environment: pitch-black darkness and pressure that could kill a human instantly.
"It's not like, you know, they can come and pull you out of some mudslide," he said.
And then he came to the realization that there was no way out, he said. Terrified he was going to die, he thought of his wife, Laurel, and possibly never seeing her again.
"I remember at one point thinking to myself, 'You know, for ABC News, I've traveled all over the world.' I think of the North Pole, the South Pole; I covered the Persian Gulf War. I almost got shot during the live shot I was doing. Bullets were flying all over the place, but I had managed to survive all that. I had managed to get away clean. But I realized at that point that this was going to be the end. And I remember very clearly, in fact, that this voice came into my head -- and I'll never forget it for the rest of my life -- it said, 'This is how it's going to end for you,'" he said.
And then a miracle occurred.
Before, there had been straining in the submersible's engine. But in the next moment, Guillen described suddenly feeling a sense of buoyancy after the pilot had maneuvered his way out.
"Because you're down there and it's pitch-black -- unless the pilot has a spotlight on it, it's pitch-black -- and so you're only going by your senses," Guillen said, adding he began to have "a floating feeling."
Guillen then turned to the pilot, a former MiG pilot, who said in a low-pitched Russian accent, "No problem."
The 2.5-hour journey back to the surface afterward was quite the ordeal, Guillen said.
They later learned that the icy current had wedged the submersible into the blades of the Titanic's giant propeller.
Experts had trained Guillen on the dangers that exist in waters that deep, but on "20/20," when Barbara Walters asked him if he would recommend the voyage to others, he emphasized the "real risk" a trip like that entails -- even if it is labeled as a tourist experience.
"This is not Disneyland," he said. "This is the real world. Mother Nature is very unforgiving."
Guillen said he believes that there must have been something "catastrophic" to cut off communication from the Titan, the submersible that lost contact on Sunday.
During his own excursion, they communicated with the surface the entire time -- not that it did them any good at the time, he said.
The passengers on board the missing Titan include British billionaire explorer Hamish Harding, businessman Shahzada Dawood and his son Suleman Dawood, renowned Titanic researcher Paul-Henri Nargeolet and Stockton Rush, the CEO of OceanGate, the operator of the tour.
The Titan, a 21-foot submersible, went underwater Sunday morning, and lost contact about 1 hour and 45 minutes later.
The vessel was designed to have 96 hours of oxygen available for all five passengers and will likely run out of oxygen by 6 a.m. EDT on Thursday, according to the U.S. Coast Guard.
Having gone through his own harrowing experience aboard a submersible, Guillen is anguished over the search for the five crew members aboard the Titan, he said.
"I'm very aware of what these poor souls on board the ship the Titan are experiencing," he said. "I am just heartbroken about it."
He added, "I wouldn't wish that experience on anyone."