CNN reported Saturday Nov 11 that the Taj Mahal Hotel had previously had warning of a possible terrorist attack on the hotel, and had stepped up precautions for a while. The nature of the warnings were not described. The precautions, such as baggage searches and sending people through a metal detector, were all oriented towards the front entrance.
Those precautions had become less intense recently. In any case, the terrorists were extremely familiar with the layout of the hotel. They came in through back doors through a kitchen and "...seemed to know [the hotel] in the night or the daytime," indicating a very high level of training for the operation.
Both the law enforcement agencies and fire fighters were found to have organizational and infrastructure deficiencies which delayed their responses and caused them to be less effective than they should have been.
The Washington Post reported Friday, Nov 28, that "...the scale, sophistication and targets involved in the Mumbai attacks were markedly different from previous terrorist plots in India and suggested the gunmen had received training from outside the country."