FAIRBANKS — For decades, the people who oversaw Fairbanks Memorial Hospital shared a comforting thought about the building — even if a powerful earthquake struck, they were confident it would remain standing.

But in the past few years, the Greater Fairbanks Community Hospital Foundation’s Board of Trustees dug a little deeper. Although they knew it would stand up under the worst circumstances, they weren’t as sure the building would remain operational.

With that goal in mind, FMH has started a $1.7 million project to upgrade the structure of the building, providing an extra dose of insurance for the only public hospital in the Interior.

“Not only do we want the people inside to be safe, we want the hospital to work,” said Niejse Steinkruger, a member of the hospital board.

FMH has weathered seismic events in the past, including a big one — the 2002 Denali Earthquake, which delivered a 7.9 magnitude rattle to Interior Alaska. Jim Loftus, who is leading the hospital strengthening effort for PDC Engineering, said even that didn’t come close to putting FMH out of commission.

But a bigger event is out there, even if it’s extremely unlikely. Loftus said the hospital is being upgraded to withstand an earthquake that statistically has only a 2 percent chance of occurring during a 50-year period.

The changes are evident at the FMH boiler facility, where thousands of feet of color-coded pipes weave through a huge room that delivers heat to the hospital. PDC Engineering did a computer analysis of each section last year and determined which pieces need to be reinforced. Metal braces have been steadily added to sections for the past six months.

Work has spread to other parts of the hospital, including braces along the walls of the two towers that are the center of its core, built in 1972.

The hospital meets modern building codes, said Jon Lundquist, associate administrator of plant operations and support at FMH. But that’s sometimes a deceptive way to look at whether a building is adequately constructed, he said, particularly a vital structure like a hospital.

“People think code is the end-all, be-all,” Lundquist said. “That’s really the minimum you’re trying to build to.”

The old standard of “life safety” — that a building could withstand collapse in a major quake — has gradually been reconsidered throughout the U.S. since the Northridge Earthquake struck Los Angeles in 1994. It caused massive damage to some buildings in the city, including critical infrastructure. The new measure, “immediate occupancy,” counts on buildings not only standing but remaining fully operational.

The issue at FMH gained momentum in recent years with discussions to upgrade the hospital’s surgery unit. As pieces continue to be added for the growing hospital, it becomes a bigger headache to access parts of the aging core.

“We’ve got old buildings in the middle and keep building around them,” Lundquist said. “At some point, we’re not going to be able to get there.”

The project to reinforce the hospital for a worst-case scenario will be a slow one, since some work will require vacating areas or depends on improvements in others. Loftus said it could be years before the final pieces are in place.

In 2012 dollars, the upgrades are estimated at $1.2 million for structural improvements and $500,000 for non-structural upgrades. Steinkruger said income from the hospital foundation’s investments will pay for the ongoing project.

She said trustees believe it’s a wise spending decision, considering the stakes involved.

“Like most Fairbanksans, I’m always assuming the hospital is going to be there if there’s a disaster,” Steinkruger said.