The phrase "action ensued" is correct and usable in written English.
It can be used to describe a situation where events or activities followed as a result of a particular action or incident.
Example: "After the announcement was made, action ensued as the team quickly mobilized to address the issue."
Alternatives: "events followed" or "activity commenced".
The Americans won easily, and legal action ensued.
Legal action ensued and the Bulls were found guilty of discrimination.
Later, Reeves was dismissed from the syndicate, and court action ensued after he was accused of trying to sell design secrets from both OneWorld and Team New Zealand to rival challengers.
Several dissenters perfected their appraisal rights under Delaware law – a statutory process permitting them to eschew the financial terms of the merger in favor of a judicially determined appraisal of fair value, taking into account "all relevant factors". This action ensued, occupying the good part of three years before Vice Chancellor Laster (VCL) of the Delaware Chancery Court.
Instead both ships opened fire with muskets until MacBride could manoeuvre away and a general action ensued.
In January 1689, a Convention Parliament summoned by the Prince of Orange assembled, and much discussion relating to the appropriate course of action ensued.
Somehow the authorities enter, a flurry of noise and action ensues, and Genaro starts running.
As production gradually unravels amid protests over the privatisation of the region's water supply, some tense, pointed action ensues.
Typical roller-coaster action ensues in the half-hour episode, as Wallace is held prisoner and meets a new love interest, Piella Bakewell, a bread enthusiast, voiced by the former Coronation Street actress Sally Lindsay.
As discontinuities or porosity develop in the coating, galvanic or electrolytic action ensues; the iron or steel, however, is protected by sacrificial corrosion, a phenomenon in which, as long as the zinc and the iron are in contact, atmospheric oxidation spares the iron and affects the zinc.
Action ensues, characters are developed, and story arcs come to an end.
