A large number of concrete panels fell from a 130-meter stretch of ceiling in the tunnel crushing three vehicles, killing nine people and injuring two others.
In case you were wondering just how large the panels were that fell on the cars—look at the photo above! They are effing huge! It was not all what I was visualizing when I heard about this disaster.
Each of the 270 concrete panels that fell measure:
- ~ 5-meters (16-feet) long x 1.2-meters (4-feet) wide;
- 8-centimeters (3-inches) thick;
- 1.4 metric tons (3,086.5-pounds).
The cause of the accident, according to Central Nippon Expressway, according to a spokesperson, was the loosening and falling out of multiple bolts used to attach the concrete ceiling slabs to the inner walls of the tunnel.
That would have been my guess, too.
The Central Nippon Expressway spokesperson adds that aging tunnel components - including the bolts—was the chief factor.
In fact, the roads operator says that they have no records showing that bolts were ever replaced or repaired after the tunnel was first completed in 1977.
As well, they admitted that rather than a hands-on maintenance check of the tunnel, they had done periodic visual checks, the last being done this past September.
Thirty-five years ago, and not once did they actual go up on a lift and check to see if there were micro-fissures? Stress fractures? Worn ceiling tiles? Stripped bolts?
Good grief! This is Japan! There are multiple earthquakes in and around the whole island chain - every single day! Gee… could it be possible that any one of those earthquakes - admittedly most are very minor ones - could actually cause some structural damage to the integrity of a tunnel?
And all the Central Nippon Expressway is doing is sending a few guys out to look up and see if it's daijobu (okay)?
A few years back in 2007, a bridge collapsed into the Mississippi River in Minneapolis, Minnesota in the U.S. (13 killed, 135 injured)… and with the immediate pressure, every single bridge in the State was checked, with numerous ones found to have serious structural compromises!
How many other bridges or tunnels in Japan are not being checked? How many others could have damage?
On a separate note… just how safe are the subways or the train line tunnels?
If the Central Nippon Expressway can let the road infrastructure suffer like this, what else could be suffering?
As an FYI (for your information), Japan has ordered all road operators with similar tunnel structures as the Sasago Tunnel (an additional 49 tunnels) to undergo emergency inspections.
Have a safe and uninteresting trip home tonight,