Vast AI experiences outage across services; users report downtime and partial recovery toddlers? Wait. We must be factual. The input is "Primary source headline: Vast AI Down" That's a general sensational. We should craft neutral: "Vast AI down" but must be sentence case and include company/product exactly: "Vast AI" is company. The headline should say "Vast AI down" but needs proper capitalization: "Vast AI down" or "Vast AI experiences outage" but avoid adjectives. The instruction: capitalize only first word and proper nouns. So "Vast AI down" would be "Vast AI down" since AI is acronym; proper noun? It's company name "Vast AI" and "AI" not a proper noun; but it's part of company name. So "Vast AI down" seems okay. But maybe "Vast AI down" is a sentence fragment; acceptable as headline? It should be a single-sentence headline. Could be "Vast AI down". Let's provide "Vast AI down". Ensure under 200 chars. Okay. Vast AI down

Original headline: "Vast AI Down"