"drastic incident" is correct and usable in written English.
You can use it when referring to a dramatic or extreme event. For example: The tornado that blew through town was a drastic incident that devastated the community.
Then there are the more drastic events: the major security incidents preceded by the auto-pilot mentality that you need to master in order to take the correct security steps in an emergency or plan an evacuation; the fear you feel for your colleagues when an incident happens.
He told the Evening Standard on Monday that the pictures gave a "more drastic and violent impression" of the incident than had been the case.
He told the London Evening Standard – for which he is a columnist – that the pictures gave a "more drastic and violent impression" of the incident than had been the case.
But for some scientists, the incidents call for more drastic action.
The increasing number of such attacks as a result of failure of Somali government to tackle its internal problem drew the attention of international community who lent a drastic response thereby curtailing the number of such incidents significantly now.
In 2015, the Palmetto state was rocked particularly by two incidents that highlighted the desire for drastic policy changes in both of these areas.
"The Tibetan Parliament is deeply aggrieved by the incidents and condemns the Chinese authorities for resorting to such drastic acts of force and repression," the exile government said.
No-one disputes that, in isolated incidents, it is best to gather firm evidence before taking drastic steps such as grounding a whole fleet.
In a letter to the work force following the sabotage incident, the labor unions represented at the plant called the situation there "drastic".
We can only hope that this incident serves as a reminder of how seemingly minor technical glitches can cause drastic market moves, and that more trading firms and exchanges deploy technology to focus on control and safety -- not just speed.
