The case cited by Anonymous is quite different in circumstances; there was a huge strike, and a large crowd of workers sabotaged the plant etc. The strike might have been illegal and or unjustified. the ratio decidendi of the case is unclear, no citation of case is given. This is not a usual misconduct, and cannot be applied in general.
The requirement for conducting enquiry depends on the category of the worker/employee. if he is a workman as defined in ID Act and if standing order applies, enquiry is required before dismissal, however grave the misconduct be. If he is not (e.g. executive/officer) he may be terminated instantly as per contract of employment. For a worker, even if his appointment letter says "you may be terminated without notice etc." such dismissal is bad in the yes of law. if there is no standing order, and model standing order is applicable, then enquiry may be conducted as per the same. mostly, managements want to send a strong signal to others by summary dismissals of delinquent workers. in such a case, the option is that the delinquent worker may instantly be suspended pending enquiry, and then hold the enquiry, and dismiss him if charges are proved. If an opportunity for defending his case is not given, by without holding an enquiry, the risk involved is that he may come back with rejoice after 5-6 years, some times with full back wages, winning the legal battle in a tribunal or court, which is a serious set back to any management. hence it is prudent to be patient enough to complete the proceedings, slowly but steadily. Also, see sec.33 (2)b, whether its applies (for giving one month's wages), which my guru says is the last nail to be put on the coffin of the dismissed employee! Agar marna tho, pyar se maro.