Mechanical technology engineering homework

Read the following article (http://failures.wikispaces.com/Big+Dig+(I+90+Connector+Tunnel) ).  With 20-20 hindsight, draw a CE (fishbone, Ishikawa) diagram to illustrate possible causes and effects.  The diagram should have been generated before construction of the tunnel, so please include other possible failure modes and other causes you can think of.  How would this diagram (developed after the accident) be of value during litigation?  You may create your CE diagram in any software program you like (or by hand), but please make sure it is pasted inside this word file for it to be graded.

And one thing is the answer shouldn't be long!