Accident vs. Incident

Accident
1- An unexpected and undesirable situation in which someone is injured or something is damaged .Accident in this sense usually occurs when you are using an equipment,tool,machine etc:

- Statics show that the cause of many accidents is system errors.
- Every year a lot of accidents happen in this factory.
- He had an accident and spilled water all over his work.
- 5000 people die every year because of accidents in the home.
- The police say the killing of the young man was an accident.
- He was killed a few days ago in a skiing/riding/driving/shooting/hunting accident.
- My third baby was an accident.

2- An unforeseen incident:
- A series of happy accidents led to his promotion.

Incident
1- An event which is either unpleasant or unusual and is unplanned and unexpected.

- The incident has triggered fresh arguments about the role of the extreme right in France.
- The foregoing account was written fifty years after the incident.
- The footballer is likely to receive a three-match suspension following an incident in yesterday's game.
- The plane took off without any incident(without anything unusual or bad happening)
- I was thinking about the humorous incident I had yesterday.

2- A serious or violent event, such as a crime, an accident or an attack:

- Three people were killed in a shooting incident in a downtown mall .
- I have witnessed many violent incidents in my life.
- The incidence brings the total of the people killed to fifteen.

3- A minor occurrence:
- Errors are inescapable incidences in the course of scientific research.
- I had an amusing incidence yesterday.

4- Something that is a part of a long series of events:

- These incidents were the latest in a series of disputes between the two nations.
- His debut at Carneige HalL was the first of a succession of exciting incidents in his life.
- The incidence was the latest in a string of attacks.

An isolated(an event that is not connected with other events) /serious/unfortunate/diplomatic incident.

- A military spokeswoman said that the shooting was an isolated incident.
- Ten people, among them 2 children, were seriously killed in the shooting incidence.

terrorist,nuclear, bomb,bombing, shooting, stabbing incident

-Many shooting/stabbing incidents go unreported.

Without incident
The voting went ahead without incident.

Notice that

• All accidents can be considered incidents, but all incidents cannot be considered accidents.

• An incident simply refers to something that has happened intentionally or not:Throwing oneself in front of a train is an incident, not an accident.

• An accident is something that happens outside of intent.

• Falling in front of a train is both an incident and an accident.

• (esp in Britain)Incident is usually used ominously to refer to specific events that somebody does not want to explicitly say:

- Your train may be delayed "due to an incident at Clapham Junction". This usually means that someone has jumped in front of a train.


References:

EnglishForums.com
Collins Cobuild-Lexicon
American Heritage Dictionary
Longman Dictionary of Contemporary English
MacMillan English Dictionary -American