When it comes to bridge collapses in Alaska, people have gotten extremely lucky. The Federal Highway Administration National Bridge Inventory classifies 136 of Alaska’s 1,675 bridges as structurally inadequate, accounting for 8.1%. Structurally deficient indicates that one of the bridge’s essential elements is in bad or worse condition. Alaska ranks 15th in the nation for the percentage of structurally defective bridges.
Given those figures and the fact that Alaska is the most seismically active state in the United States, it’s surprising that no one has died as a result of a man-made bridge collapse. Since 1900, the state has suffered one earthquake with a magnitude of 7-8 every year. In addition to the larger quakes, the Alaska Seismic Hazards Safety Commission reports about six magnitude 6-7 earthquakes rock Alaska each year.
When all sizes of earthquakes are included, the state experiences more than 1,000 tremors per month.
Although man-made bridges have collapsed in Alaska, people have escaped catastrophic injury. There have been a few severe collapses of natural bridges throughout the state, culminating in catastrophe. We’ll talk about both sorts of structures as we investigate the four most devastating bridge collapses in Alaska.
The Miles Glacier Bridge
The bridge which spans the Copper River in south-central Alaska, was built in the early 1900s and cost $1.4 million. According to Nerd Wallet’s inflation calculator, that money is now equivalent to $44.5 million. However, the bridge was well worth the high cost at the time.
The Copper River & Northwestern Railroad used the Million Dollar Bridge to transport $200 million of copper ore from the world’s largest copper mine in the Wrangell Mountains. It was the longest steel bridge on the 196-mile Copper River & Northwestern Railway, measuring 1,550 feet. In 1938, the Kennecott Copper Corporation closed the mine and abandoned the bridge.
Almost 30 years passed before the Million Dollar Bridge was turned into a highway bridge in 1962. Its life as a roadway bridge came to an abrupt end barely two years following its transformation. The bridge was severely damaged by the Great Alaskan earthquake in 1964.
The cataclysmic earthquake severed the bridge’s northmost span, plunging it into the river. Another nine years passed before restoration work was completed to restore the bridge’s ruptured rivets and damaged concrete. However, high-water events in the 1990s caused further damage to the Million Dollar Bridge.
The bridge, which spans 30 feet above the river, was listed on the National Register of Historic Places in 2000. In 2005, the Million Dollar Bridge reopened and began serving highway traffic again. Since 2011, the Copper River Highway has been closed beyond mile 36 due to a washed-out bridge. Bridge 339 in Cordova, Alaska, is literally the end of the road, yet the Million Dollar Bridge is still accessible via boat.
Kenai River Bridge
The Great Alaskan earthquake, commonly known as the Good Friday earthquake, devastated the state on March 27, 1964, killing 115 people and demolishing hundreds of structures. The quake measured 9.2 on the Richter scale, making it the greatest earthquake in US history and the second largest in the globe.
Along with the tremendous shaking, a tsunami of up to 220 feet inflicted casualties and damage from Alaska to Northern California. The Kenai River Bridge, like the Million Dollar Bridge and 90 other structures, buckled under the force of the massive earthquake.
A newspaper article describes the experience of a family whose attempts to flee the shaking were stopped by the destroyed Kenai River bridge. Mona Painter was at home with her children when the earthquake occurred. She reported the home as “breaking up” around them, so they ran to their automobiles and drove to the Kenai River bridge. When they arrived, they were horrified to see their bridge vanished.
“The bridge was gone!” Painter stated. “It split into pieces and landed in the river. The river was black with enormous whirlpools and was draining back into the lake. It was dreadful! I assumed it was the end of the world.
Snow Bridge at Mount McKinley
Denali, once known as Mount McKinley, is a lethal mountain. For every 100 successful summits, nine people die. Falling is the cause of 45 percent of these deaths. The way up the peak is strewn with gaping crevasses that climbers cross using snow bridges.
When these snow bridges fail, the climbers who cross them frequently fall along with them. One of these disasters happened in 1986, when two French climbers fell more than 75 feet to their deaths.
“A 10- to 30-foot-thick snow bridge just gave way under them,” said park service ranger Ralph Moore, who assisted in recovering the remains from the chasm.
Ice Bridge at Mount Hunter
Mount Hunter is the steepest and most technically challenging of Denali National Park’s three big peaks. Less than 40% of those who attempt to climb to the summit succeed. In 2022, a Japanese climber perished at an elevation of approximately 8,000 feet near his team’s camp on the southeast fork of the Kahiltna Glacier.
The 43-year-old man was attempting to cross an ice bridge when it crumbled and he fell into a fissure at the base of Mount Hunter’s North Buttress. He was unroped from the rest of his squad when he fell.
National Park Service climbing rangers tried to collect the man’s body by descending into the crevasse. According to park officials, the narrow fissure was filled “with a large volume of snow and ice approximately 80 feet below the glacier surface” as a result of the ice bridge’s collapse. The ranger was unable to descend further to retrieve the body.