CHENNAI: A 53-year-old SSI (special sub inspector) died of heart attack on Wednesday morning in Avadi while undergoing training for the post of sub-inspector. The deceased was identified as Prabhakaran of Pattabiram, attached to the Central Crime Branch (CCB) in Avadi. Police sources said that Prabhakaran was undergoing training for promotion as SI since November 4. On Wednesday morning, as he was preparing at the battalion camp in Avadi, he collapsed and fell after which his fellow policemen rushed him to the GH where he was declared as brought dead.