It was a cold night of Nov 26, 2008, when 10 heavily armed Pakistani terrorists brazenly entered Mumbai through the virtually unguarded Arabian Sea route. Shortly afterwards, they unleashed a brutal terrorist attack on several prime locations in south Mumbai spread over a four-five square km area, leaving 166 people dead and the world shocked.
Here's what happened and the subsequent events that finally culminated in the hanging of the sole gunman caught alive - Mohammed Ajmal Amir Kasab.
The list of the wanted accused in the 26/11 Mumbai terror attacks
The 2008 terror attack, which exposed chinks in coastal security, impelled the government to expedite measures to improve both physical and electronic surveillance along the country's 7,516-km-long coastline.
A book claims that a Major Iqbal of Pakistan's Inter Services Intelligence boasted of a super agent dubbed 'Honey Bee' in New Delhi who passed them classified files on the training manuals of Indian police and army commandos.
Patil said that in the aftermath of the 26/11 attack, India has effectively proved to the international community that it was perpetrated by the Lashkar-e-Taiba.
Headley, a Pakistani American from Chicago, had visited India several times ahead of the 26/11 attack to recce the city and choose sites, including the Taj Mahal hotel and Chabad House, for the attack.
The terror strike seems to have almost faded from public memory like an old nightmare, as survivors and families of victims, and the people of the city, get on with their lives.
The country's coastal security is much better and intelligence sharing has improved, but the police-population ratio remains inadequate, intelligence gathering needs to be beefed up and more anti-terror mock drills need to be held across the country, the experts said.
The NSA cautioned that South Indian shores may be used by terrorists to infiltrate using high seas and security agencies have to be alert to thwart any such attempt.
India heaved a sigh of relief when Kasab was secretly hanged in Pune's Yerawada Central Jail on Nov 21, 2012.