For one, it was another eleventh day of the month, similar to September 11. Even bigger, is that ETA in recent times, has not been particularly violent. They've destroyed a lot of property, but they often send a message to officials or the police that they've set a bomb--so that the building or other property can be evacuated.
Although there was one incident recently in which at least two people died, it was because those two had not gotten notice of the bombs, because they were in their vehicles. The rest of the building evacuated.
There wasn't such a warning for that Madrid train bombings on March 11.
Thanks, J Aguilar for posting about 3/11. You're the source for anyone looking for a true investigation of 3/11...it is incredible that the US MSM has black-listed any info on this...IMO, there is a lot of damage to come to the European Left and their buddies in the US are running scared and blocking any news.