One shot by pve in HiSec data/relic sites

[Pierre_de_Bricassart]

Wait, déjà vu?

All blowed up, no warning? (NPCs)

When I get targeted, I hear my ship try to target back. Was just running a data site, npcs showed up and poof! My ships gone. No beeps, no target back, nada. The kill report came up before my ship blew up. It was a data site, I think the npc was sentry. Do they not need to lock on maybe?