With the benefit of the initial factual report
Both engines failed to repond at the same time in a critical flight regime from a presumably low power (flight idle?)
Additional unverified reports suggest that a loud engine running noise was heard before impact
Some have commented on the different conditions of the two fans (one with many broken blades, filled with dirt and one with much less damage and the dirt only seen in front of the fan)
Possibilities include a common cause associated with both engines (either at the engine level or the aircraft system level) and that one engine may have belatedly responded.
If the part in the bolded is correct than that area deserves the most attention in the next briefing