They’re still doing a “fault tree analysis” that will ultimately point to a root cause of the scrub.

In a statement, the company said the investigation is preliminary and that “all plausible causes are being tracked in an extensive fault tree and carefully investigated.”

In engineering-speak it’s called a fault tree analysis.

"That's all we can say with confidence right now. Will have more to say following a thorough fault tree analysis."

“Will have more to say following a thorough fault tree analysis.”