WW2 British bomb found in Koblenz causes 45000 people evacuation
 

...the biggest since WW2!

http://www.thelocal.de/national/20111130-39193.html

probably a 4000 lbs cookie, apparently the Rhine is giving back a lot of these bad boys lately!

A 1 mile blast radius? Really?

oh yes, 4000 lbs ain't no lightweight, it's the same weight of an average car.

I'm sure you've seen this before, and this is "just" an SC500 bomb
http://howbigreally.com/dimension/wo...blast#mk12_5hn

One step frwd in understanding what means "carpet bombing" ;)

Still a threat after all this time,wow. Do you now if there has been any cases of ww2 ordnance actually going off? I know land mines are still a problem in some parts of the world but most of those are quite modern aren't they?

there are many cases of unexploded ordnance being found in Europe after WW2, from small stuff to bigger ones. The main issue is that explosives tend to become unstable with time and humidity, hence the extreme care in these cases. Unfortunately there have been accidents where things went wrong, since neutralising these threats is not an easy task.

My brother is an archaeologist, he knows of my interest for WW1 and WW2 and called me on a couple of occasions asking me if I could help him identifying some suspect items his team stumbled upon whilst digging in the countryside near Anzio: whenever they go check on freshly ploughed fields there's SO much stuff coming up! Once they saw a little wooden box half buried, with what seemed like a fuse sticking out, he took a pic of it and texted it to me, I called him and said "stay well off that!! It's not a wooden box, it's a mine!!". I sent him the same day via express courier a manual with pics of the most commonly found landmines and ordnance of WW2, which he now keeps with himself all the time.
In a month they found two Schu-minen 42, 5 Teller and loads of ammunition in 40 acres of land!!

an interesting read on the topic can be found here

http://maic.jmu.edu/journal/4.2/features/ww2/ww2.htm

Its scary to think of all the unexploded munitions lying around. I saw a programme about a French bomb dispoal team a while ago, and I think they said they had enough work to last the next several hundred years!

I know, it's madness, and unfortunately there's not much that can be done.
When I was still in Italy I remember they found a 1000lb US bomb on the station I used to take my train to uni every day: the bomb was literally 10 metres under the platform I used to walk back and forth on everyday waiting for my train (!!!).

btw, "blast radius" doesn't mean that everything within a mile will be destroyed! That's the theoretical reachout of splinters and shockwave, but obstacles like building or terrain will deflect/modify it.

The "total destruction" radius is - afaik - about 100m, at 1800m glass windows will still be broken. The rule by thumb is, when the defuse a bomb, 1m for every kg, so they evacuate 1800m for the 1800kg of that bomb.

The special situation in Koblenz is that the bomb is in the river - and the slopes of the river valley are all covered with houses right to the tops. Therefore the bomb is figuratively in the center of a funnel, so no "obstacles like building or terrain [that] will deflect/modify it".

I've seen it last Saturday from a balcony right above it - being there on a visit. The probability is *really* low, but still they are *really* nervous...