An investigation must be made immediately after the accident occurred, or within the time as soon as possible in order to get the correct facts. And don't forget those witnesses detail why the event is important.
The investigation shall be made immediately after the accident. Or within the fastest time to get the facts right. The event also witnessed the incident, and do not forget the important details such.
The investigation will be made immediately after the accident. Or in the fastest time to get the facts right. Witnesses the event and not important details.