Nice Conspiracy Carmela
but would the Mafia done it on May 23rd rather then today? Or maybe the SCU are threatening the authorities after the bust last week?
This whole time right now on through July when Borsellino was murdered are referred to as the Capaci Massacres. So, if this is what it's all about, then it could be from now all through July. If that's what it's about.
Bust last week is another possibility and hitting a school is something of a symbol for the mafia, albeit disgusting. They have a saying in Italy "La mafia teme piu la scuola che la giustizia" meaning The mafia fears school more than justice.
Also, the exact timing of this bomb was intended to kill, as it was set for the exact time the girls would be arriving. That's the saddest part.