I-5 bridge over Skagit River collapses

[Kniwt]

http://www.king5.com/news/local/Report-I-5-bridge-collapses-over-Skagit-River-cars-in-water-208758631.html

Washington State Patrol confirms an I-5 bridge over the Skagit River has collapsed and at least two cars with people inside are in the water.

picture at the link

[KEVIN_224]

http://www.kirotv.com/news/news/i-5-skagit-river-bridge-collapses-people-vehicles-/nX2d5/
http://goo.gl/maps/Wt5u0

I just saw the same story over at KIRO-TV (CBS) channel 7. Wow!

[vtk]

I hate to be the guy whose immediate response to misfortune is to think about how it might advance a political agenda...

I hope nobody was killed...

...but come on, there's no good reason for us not to invest more in our infrastructure.

[rickmastfan67]

Just saw this on my local news as well.  Crazy.  At least not as many cars as the I-35W collapse, but still, this shouldn't be happening.  Does anybody know if the bridge was under-construction like the I-35W one?

[Big John]

Just saw this on my local news as well.  Crazy.  At least not as many cars as the I-35W collapse, but still, this shouldn't be happening. 

I traveled across it and thought it was under-designed for an interstate bridge, so I suspect it was a repurposed US 99 bridge

[Kacie Jane]

Just saw this on my local news as well.  Crazy.  At least not as many cars as the I-35W collapse, but still, this shouldn't be happening. 

I traveled across it and thought it was under-designed for an interstate bridge, so I suspect it was a repurposed US 99 bridge

I believe the bridge was built in the 50s, slightly predating the interstate designation.  And no, not under construction.

[seicer]

And not structurally deficient either.

[rickmastfan67]

Just saw this on my local news as well.  Crazy.  At least not as many cars as the I-35W collapse, but still, this shouldn't be happening. 

I traveled across it and thought it was under-designed for an interstate bridge, so I suspect it was a repurposed US 99 bridge

I believe the bridge was built in the 50s, slightly predating the interstate designation.  And no, not under construction.

I heard on this live feed about the bridge collapse that it was built in 1955.

[golden eagle]

Just saw this on MSNBC. Hope there are no deaths.

[sp_redelectric]

And not structurally deficient either.

Some Tweets I'm getting are saying "functionally obsolete"...meanwhile KOMO 4 finally has a helicopter with live shots NOW.

[Kacie Jane]

I saw that term "functionally obsolete" being thrown around, and I'm curious, does that actually mean the same thing as "structurally deficient"?

Because a bridge can have four lanes of substandard width in a location that probably calls for six, be functionally obsolete, and still have the strength to stand for several decades.

[Brandon]

And not structurally deficient either.

Some Tweets I'm getting are saying "functionally obsolete"...meanwhile KOMO 4 finally has a helicopter with live shots NOW.

Functionally obsolete doesn't mean it should be in imminent danger of collapse.  It may merely mean a lack of shoulders.

Looks like it was a steel truss.  Anyone know if the structure was non-redundant, like the I-35W Bridge?



There does seem to be a detour route, looking at Google Maps along College Way, Riverside Dr/Burlington Blvd, and George Hopper Road.  Was Riverside Dr/Burlington Blvd there former US-99?

[Alex]

Yes, 1955 per the non-functioning Nationalbridges.com:

A 1955 steel through truss bridge carries Interstate 5 across the Skagit River. The four-lane freeway leaves Mount Vernon and enters Burlington.

More photos at Interstate 5 North: Skagit County and Interstate 5 South: Skagit County

[Big John]

And not structurally deficient either.

Some Tweets I'm getting are saying "functionally obsolete"...meanwhile KOMO 4 finally has a helicopter with live shots NOW.

Functionally obsolete means it can't smoothly handle current traffic loads or has geometric deficiencies such as narrow lanes or narrow/non-existent shoulders.  I agree that the bridge had geometric shortcomings.  And note that "structurally deficient" is more serious than "functionally obsolete" so if a bridge is both it is considered "structurally deficient", so that bridge had an acceptable structural rating.

[Big John]

Looks like it was a steel truss.  Anyone know if the structure was non-redundant, like the I-35W Bridge?

Like almost all truss bridges, this was also non-redundant

[on_wisconsin]

Screen cap from KOMO-TV:

[kkt]

Yes, it had inadequate shoulders, and if space and money were available it would be nice if it were six lanes, but that's not supposed to mean it's in imminent danger of collapse. 

We already didn't have enough money for the new Evergreen Point Bridge, the new Alaskan Way Viaduct, and the new I-5 bridge over the Columbia, so we can add this to the list of needed projects we can't afford.

[Big John]

Yes, it had inadequate shoulders, and if space and money were available it would be nice if it were six lanes, but that's not supposed to mean it's in imminent danger of collapse. 

The Functionally Obsolete label does not mean there is anything structurally wrong with the bridge, but makes it eligible to receive federal funds to modify or replace the bridge to bring it up to modern geometrical standards and to handle the design traffic counts.  Note that eligibility doesn't necessarily mean they will receive the funds if requested.

[on_wisconsin]

Capped from KIRO-TV:

[TEG24601]

The bridge was originally built in 1953, as part of the PSH 1/US 99 Bypass of downtown Mt. Vernon and Burlington.  The bridge is a non-redundant steel truss bridge.  The bridge just passed an inspection, but was functionally obsolete, mainly because it was often jammed during holiday weekends, and was only 4 lanes without interior or exterior shoulders.  From what I recall, it was to be replaced in the mid-2000s, but that plan was shelved when funding was lost due to I-695, and most road funding was moved into fixing dangerous roads, like SR 20, instead of updating infrastructure.

It is only a matter of time before something like this happens on other bridges in Washington, like the entire section of I-5 through Seattle, which is basically a continuous bridge for 10+ miles.

[KEVIN_224]

Is it fair to compare this collapse to the I-35W bridge in Minneapolis, on August 1, 2007? As soon as I heard this story, that's the first thing which came to mind.

[Big John]

Is it fair to compare this collapse to the I-35W bridge in Minneapolis, on August 1, 2007? As soon as I heard this story, that's the first thing which came to mind.

Unlike at I-35W, there was no increased loading from construction activities.  Otherwise it was similar as in it was a fracture-critical bridge collapsing with as little as one element failing due to no redundancy.

[rickmastfan67]

KIRO-7 just said that a wide-load semi might have hit a girder that made it collapse per a witness who was on the bridge when it happened.

EDIT: Now a DOT representative is saying it's very possible that a over-height semi hit a girder causing the bridge to collapse.

[sp_redelectric]

Some folks on Amtrak Cascades are upset, BNSF has held traffic from crossing their nearby bridge for an inspection before they are clearing trains...there's a Vancouver, BC bound train stopped south of Mount Vernon right now.

And I did not mean to imply "functionally obsolete" to mean dangerous or unsafe...about 56,000 vehicles per day cross the bridge but definitely a major route between Seattle and Vancouver, the two largest metropolitan areas of the Pacific Northwest.

[rickmastfan67]

On the KILO-7 feed, they are showing the truck that MIGHT have brought the bridge down.

EDIT:  Here are pictures of said truck that might have taken down the bridge segment.