Rikuzen-Takata, Japan (CNN) -- At a hospital in northeastern Japan, the remnants of lives stolen in seconds are scattered on each of its four floors.

Metal beds are bent, I-V bags are filled with muddy water, and blood pressure monitors sit underneath splintered trees.

But Takata Hospital nurse Fumiko Suzuki doesn't just see the damage, she hears the haunted screams of the patients she could not save.

"The patients couldn't walk," said Suzuki, recalling the moment the tsunami hit.

"I heard someone screaming, 'Auntie, I can't save you. I'm sorry.' Then she ran out of the room."

Suzuki said a glance out of the window revealed a wave as high as the fourth floor.

The nurse said she told the patient "I'm sorry" as she raced up the stairs.

"If I tried to save this person who was lying on the bed, I would have lost my life as well," she said.

Suzuki pauses, grief etched on her face.

"It is the biggest regret I have," she said of leaving patients behind.

The tsunami following the 9.0-magnitude earthquake on March 11 engulfed every floor of the hospital just as Suzuki stepped onto the roof. At least 10,901 were killed nationwide.

Of the 51 patients hospitalized, doctors and nurses could not move 12 and they drowned in their beds, said Mikihito Ishiki, a medical director at the hospital.

One patient died as the hospital staff moved him to the roof while two more died on the frigid roof awaiting rescue.

"Ten of my staff also died with the patients," Ishiki said.

The doctor lost his staff, his patients and the hospital he proudly called his home. His wife remains missing and is presumed dead.

As soon as rescuers plucked the doctor from the engulfed building, he started working from a makeshift clinic on higher ground.

The doctor's composure cracks as he lifts a handwritten note from a satellite phone sitting in his clinic.

"Yokosawa is helping us from heaven," he reads, referring to a 60-year-old hospital administrator, Shigeru Yokosawa, set to retire in April.

After the tsunami warning, Ishiki asked Yokosawa to find the satellite phone on the first floor of the hospital.

Satellite phones are vital lines of communication after a natural disaster because phone lines are usually knocked out.

Yokosawa got the phone and moments before a massive wave swallowed him, tossed it to a colleague, who ran to the roof.

Seconds later, the tsunami engulfed the hospital.

His sacrifice is part of the reason Ishiki won't leave this clinic, now fully operational and treating patients across Rikuzen-Takata.

His fellow survivors tirelesslesly work along him.

Suzuki, who brought her elderly and sick mother to the clinic, said the doctors and nurses can't feel guilty for surviving the disaster.

"When I hear that," she said, "it breaks my heart. It's a natural disaster. They want to save everyone, but in this situation, they can't."

Suzuki said she is grateful to see familiar faces of her colleagues, and hope they realize they are making a difference in the present.

She pushes her pain -- the loss of her home, her friends and her relatives -- to the back of her mind as she focuses on her patients.

The town has given her not just a refuge from the pain, but donations of clothes for days she's not wearing her nurse uniform.

"Whatever the situation, I will stay here. Talking with the patients will be my cure. I feel like I'm not the one taking care of others, but the one being taken care of," she said.