First and foremost thing Employer need to ensure is to get medical help to the injured person.
If accident is fatal, he should be rushed to a good hospital casualty department or emergency department and get medical aid. Accident report, intimation to Labour deptt/factory inspector could be done within 48 h0urs from the time of accident.
Getting urgent medical help to the injured who met with an accident in the factory premises, is first priority, which is not only a legal obligation of employer, but also ethical/moral/humanitarian obligation of an employer.