Sequence reached maximum value

Postgres. At 09:14 every INSERT into the events table began failing with nextval: reached maximum value of sequence "events_id_seq" (2147483647). The table's id is the primary key. Writes to this one table are fully down; reads are fine. The table has billions of historical rows (many since deleted). There was no deploy. Triage, restore writes with minimal downtime, and prevent recurrence on other tables.