History: Railroad bridge collapse isn’t the first in Tempe’s history.
Flooding wiped out portion of trestle in 1891
A railroad bridge that collapsed over Tempe Town Lake on Wednesday had withstood more than 100 years of flooding and devastation.
The steel-beamed trestle bridge was built in 1912 to carry cargo across the then free-flowing Salt River. It had been reinforced over the years but most of its original construction remained intact.
It was the longest-standing railroad bridge in that area, surviving destructive floods that caused extensive damage to its predecessors and several nearby bridges.
Tempe’s stretch of the Salt River, which today includes the 2-mile Tempe Town Lake, has seen its share of bridge collapses, train derailments and even a dam break.
Flooding and bridge collapses
The first railroad bridge over the Salt River was built in 1887, connecting Tempe farmers and other settlers to Phoenix and other parts of the Valley, according to Joshua Roffler, with the Tempe History Museum.
But the Salt River was prone to flooding. In 1891, a historic flood wiped out a portion of the railroad bridge, along with adobe homes along the river.
About 10 years later, flooding weakened a second bridge. During a dry season, the weight of a train caused the pylons to collapse, plunging the train with cattle and merchandise into the dry Salt River about 20 feet below. One man died and several others were injured, according to a 1902 article in The Republic.
Over the next couple of years, floods washed out efforts to build other bridges.
The 1912 railroad bridge, the site of Wednesday’s fire, was built by American Bridge Company and owned by the Arizona Eastern Railroad Company. It is the last remaining railroad bridge in Tempe.
The bridge features a nine-span steel structure with Pratt-type trusses, which were favored for their “simplicity, economy of metal, and other engineering features,” according to a history of rail engineering in the Library of Congress.
The Salt River’s water flow eventually was moderated by the opening of the Roosevelt Dam in 1911, about 70 miles east of Tempe on the upper Salt River.
But floods still wrought havoc on Valley transportation.
In 1980, a major flood swept through the Valley, washing out Salt River crossings, leaving only the Mill Avenue bridge and Central Avenue bridges intact. For a period of time, the only way between Tempe and Phoenix was via train.
In January 1993, another storm swept through the Valley wiping out a span of the Mill Avenue Bridge that was under construction.
Creating Town Lake
The Salt River was further dammed through the years, creating a largely dry riverbed.
The scarred, empty river inspired an Arizona State University professor to consider how to revitalize the area. Architectural students in 1966 created plans that included building a lake.
Valley voters rejected a tax hike to fuel the project in 1987, but Tempe leaders pushed forward and began construction of the lake a decade later.
The lake was billed as a way to better control flooding and open the area to development, which it has achieved over the past 20 years. Town Lake today is flanked by apartments, condos and modern office buildings. Some 2.5 million annual visitors kayak, attend festivals and hang out by the lake.
Dam broke 10 years ago
But the lake created its own emergency 10 years ago this month, when warning sirens wailed into the night.
At 9:44 p.m. on July 20, 2010, one of the four rubber bladders burst on the lake’s west end, sending a rush of water into the dry Salt River.
Former Mayor Hugh Hallman and his wife had just gotten home when the phone rang.
“Mayor, we got a problem.”
No one was injured, but by the next morning, most of the nearly 1 billion gallons of water in the lake was drained. Pools of muddy water, dying fish and exposed trash that included traffic barricades, ladders and 55-gallon garbage bins were left behind.
Town lake remained closed for nearly three months as crews installed a temporary fix.
A dam with hydraulically operated steel gates was completed in spring 2016.