FARINDOLA, Italy -- The strain showed on Fabio Salzetta's face.

The maintenance worker at the luxury Hotel Rigopiano who escaped being buried under the deadly avalanche because he had gone to check the boiler told Italian media Saturday he called for hours to find survivors, but no one responded.

The scene, he said, "felt like it was a dream. It was a nightmare."

One of the people buried inside and among the 23 still missing is his sister. His voice shaking, he said he last saw her in the kitchen.

Five people have been confirmed killed, including two hotel waiters.

Nine, including four children who had been on family vacations, have been pulled alive from the reinforced concrete structure buried beneath as many as 24 feet of snow Wednesday.

Doctors at the hospital in Pescara said one of the adults underwent surgery for a crushed arm and was in fair condition, but all of the other patients were doing well. The children were being moved from intensive care to the pediatric ward.

Buoyed by the rescues Friday, more than two days after the disaster, search crews were intensifying their round-the-clock operation, fighting against the clock and deteriorating weather conditions, including fresh snowfall and freezing temperatures.

"The research is difficult also because the site is in a precarious equilibrium; that's why the interventions are made very carefully and why we cannot intervene with big machineries risking to modify a very vulnerable situation," said Titti Postiglione of Italy's civil protection agency.

Instead, workers pushed ahead using saws, shovels and gloved hands, listening for sounds that might suggest more survivors.

Dozens of friends and family members kept vigil at the hospital, some growing frustrated at the lack of news.

In one family, elation that 9-year-old Edoardo Di Carlo had survived in good condition was tempered by news that his mother, Nadia Aconcciamessa, a nurse in the nearby town of Penne, was among the dead.

The toll includes two waiters at the hotel, Gabriele di Angelo and Alessandro Giancaterino.

Postiglioni said the high number of people still missing was giving impetus to the search. They include Di Carlo's father and the parents of 6-year-old Samuel Di Michelangelo.

The search included sending sound-sensitive instruments down into snow-crusted debris.

Rescuers passed crates full of chunks of hardened snow and ice to colleagues as they tried to penetrate deeper into the wreckage, creating the rough equivalent of elevator shafts to allow searchers to descend into the smashed hotel.

Searchers also used devices that could pick up any electronic waves emitted by cellphones of the missing, said Walter Milan, a spokesman for the alpine rescuers.

That voices haven't been heard lately doesn't mean no one is still alive, he said, explaining "we know that thick walls and snow isolates" possible voices.

Because of the continued avalanche risk, escape routes were planned for rescue crews and each participant was equipped with a tracking device in case they were buried under the snow.

Snowfall higher than 10 feet thwarted the arrival of heavy equipment like cranes, said rescue spokesman Marco Bini, leaving the searchers to often rely on their hands or simple snow shovels to make progress.

Salzetta has been spending time at the hotel rescue operation advising crews on the hotel's layout and guests' possible locations.

Talking to reporters as he left the area, he recalled the guests had gathered to go home, some shaken by the four quakes that day, but their departure was stymied by heavy snowfall that had made the road out of the area impassable.

"In the end, they were calm. No one imagined that something like this could happen, after all the earthquakes that there have been," Salzetta said.

The last thing he remembers of that night: "The snow. Everything snow."