What was the worst bug you've ever solved ?
cmos: In high school I got a job for my local Department of Public works in the Power division.  I lived in a small New England town that did their own power, much like most towns do their own water and sewer.My job was as an assistant to the inventory guy, a 70 year old feisty man with one hand named Al.I was often bored when Al would tell me to 'go hide somewhere' so I wrote some software to help him manage the inventory system.  The power engineers in charge saw this and after a few small programming assignments had me work on updating the newly installed SCADA control system.  This was a specialized programming environment that controlled all the power in the town.We were setting it up to buy power from the local college during the yearly 'peaks' in August, thus reducing our yearly electrical bill by potentially millions of dollars.After a month of working on it and incrementally adding my changes I screwed up.  I knew this when I submitted a change and all the alarms went off at the substation.Half the towns power was out.  I got it back on after an hour, and nobody called with ventilator issues, so I think there was no real harm done.The engineer in charge of the department laughed it off when he saw my apprehension about the situation.  He said in the grand scheme of things they have made far bigger mistakes than that, probably referring to the blown transformer a couple months earlier.