Cracking the crank

Remember sometime ago I changed my engine due to a strange knocking sound, I thought at the time that it was a bad rod bearing, as it followed the rpm´s.
Well last night I had hired my friend Allan aka Flenne racing to help me assemble the short block. It was a scary experience when we saw the crank, it was cracked just after cylinder number 2. I have only heard about cranks there had cracked never seen one, and have in mind that this engine were still driving!!!
This was a set back for the Express project, but lucky for me I have yet another spare industrial engine sitting with only 47 hours on it.