KINGSTON, Jamaica— President and chief executive officer of the Jamaica Public Service (JPS) Hugh Grant says the company is looking into a “cascading” shutdown effect set off by lightning that caused the islandwide blackout experienced Friday night into Saturday morning, describing the phenomenon as unexpected. “We lost five of our transmission lines emanating from one of our significant substations in the corporate area. In parallel with that, we had a cascading effect, causing a loss of generation across the entire island.