[STARLIT]

“There’s a ring around the engine that’s meant to contain the engine pieces when this happens,” Goglia said. “In this case it didn’t. That’s going to be a big focal point for the NTSB: why didn’t [the ring] do its job?”

Photos posted by passengers showed a heavily damaged window near the damaged engine. The Boeing 737 apparently blew an engine at 30,000ft and was hit by shrapnel that smashed a window, damaged the fuselage

[Cboldt]

The containment system is designed to — and almost certainly would — contain one blade. From the damage in those views, looks like much more than one blade cut loose.

[Axenolith]

Probably 99 times out of a hundred if a turbine is going to scatter it’s going to do it under the highest loads at rollout/liftoff and during ascent. Toodling along at 30+K feet is like being on cruise control for them. I’d posit the protective fragment shroud is titanium or some type of ceramic composite that’s some value more brittle at cruising altitude than at lower elevation where the majority of failures are expected to occur. A failure at cruising altitude, under this hypothesis, would incur more damage, but probably still within design parameters where the aircraft stays aloft and controllable.