Incident Postmortem Drafter

Draft an incident postmortem for the following:

Incident: [BRIEF DESCRIPTION]
Date/Time: [WHEN]
Duration: [HOW LONG]
Impact: [WHO/WHAT WAS AFFECTED]
Detection: [HOW DID YOU FIND OUT]
Resolution: [WHAT FIXED IT]
Root cause: [WHAT BROKE]

Write a blameless postmortem covering:
1. Summary (3 sentences)
2. Timeline (UTC, key events)
3. Root cause analysis (5 whys, with concrete causal chain - not generic phrases like "human error")
4. What went well during response
5. What went poorly
6. Action items (specific, owned, dated)

Maintain a blameless tone - focus on systems and processes, not individuals.