This time we got lucky. This time, when train cars carrying hazardous materials went off the tracks in the Howard Street tunnel Thursday morning, there was no leak — unlike the similar accident in 2001, when cars leaked materials including fluorosilicic acid.

Back in 2001, CSX said it was not responsible for the Howard Street tunnel accident. The railroad blamed the city, saying a water main leak caused the derailment and the subsequent fire that burned in the tunnel for days. The railroad admitted no wrongdoing but did agree to pay the city $2 million to settle a $12 million lawsuit. A National Transportation Safety Board investigation was unable to determine the accident's cause.

The NTSB said of the 2001 accident that the "most likely derailment scenario involved an obstruction between a wheel and the rail, in combination with changes in track geometry." But the NTSB report said that damage from the chemical fire, flooding from a resulting broken water main and recovery efforts destroyed the evidence needed to determine a cause.

A year after the accident, the railroad said there was a minimal risk of it repeating.

This time, there was no mention of a water main break. CSX, it would seem, owes the city an explanation for what happened Thursday. Some would say it still owes Baltimore an apology (and perhaps some cash?) for what happened in 2001.