After four days of madness, painful deaths, anxiety and national shock, the Westgate siege is over. Or so the government would have us believe. Seventy-two people dead, including five of the attackers, hundreds more injured and 11 arrests made in connection with the attack. But a lot of questions remain unanswered.

What exactly happened to the hostages who were said to be held by the terrorists inside the mall? If there were about 15 attackers, and five of them were killed, what happened to the rest of them? Did they escape? Rumours have indicated that some of them could have got out as freed hostages.

Many of the victims had been to Westgate countless times: for meetings, concerts or just a cup of coffee with friends. Within minutes, the suburban district of Westlands in Nairobi, where Westgate is situated, was turned into a war zone. Military helicopters were hovering overhead day and night for the four days of the siege. Ambulance and police sirens rent the air continually. Gunshots and blasts from inside the mall were occasionally heard. This was what I imagine a war zone looks and feels like, or living through a scene in an action movie.

This has been a scary time for Kenyans, and especially for those who live in Nairobi. I could not sleep on Saturday night. I left Westgate as darkness was falling as I was sure it would all be over by morning. But I stayed awake, tuned to Twitter, until around 3am. The morning brought the bad news that the nightmare was far from over.

It was not over until two days later on Tuesday evening when the president finally addressed the nation to claim victory over the attackers, and declared three days of national mourning in honour of those who had died.

But even as the mourning starts, we must ask the hard questions: How did we find ourselves in this situation in the first place?

It was bad enough to stand there and see the horror in the faces of those who had escaped, and heart- wrenching to see the pain and agony on the faces of those who did not know the fate of their loved ones trapped inside the mall or missing.

Children were wheeled out of the mall in shopping trolleys, men and women ran out screaming, drenched in their own blood.

I interviewed many people and their stories left me sad and angry at the same time. Sad because I related to every detail of the narration – I live in Westlands and have been to Westgate countless times – and sad because most of these stories told of dead children lying on the floors and of screaming pregnant women.

I was also sad because I knew some of the people who were injured on the day and some who had had narrow escapes.

But as the initial shock passed, I was angry.

One Somali Muslim woman told me how she had communicated with the attackers inside the mall using the phone of a dead loved one. The dead man was her relative and she had called him to find out whether he was alright. But one of the attackers had answered. They were sorry to have killed him, the attacker had said. They did not know he was Muslim and they had not intended to kill Muslims or Somalis.

This woman I interviewed went to tell the police that she was talking to one of the attackers, but they ignored her. She even managed to sneak through layers of security personnel and got to a chief police officer leading the rescue operations, but he brushed her off as well. She talked to the attacker a good three times on that day, but no one took her word seriously.

This is when it gets annoying. Who in the world does that? Who trains our officers? How can a troop of heavily armed terrorists have made their way through Nairobi traffic to the mall unnoticed?

"As long as our systems and structures remain the same, we should not expect anything to change after this attack," says Dr Robinson Ocharo, a sociologist and lecturer at the University of Nairobi. "In fact, things could only get worse because we have been hit once – twice will be worse. Our enemies would only need to study our behaviour and our responses."

As a country, we had it coming. It is a known fact that anyone willing to pay for it can get Kenyan citizenship. Rumours abound of people crossing into Kenya from Somalia and paying "very well" not to have their bags checked.

International wanted criminals have found a home in Kenya simply because they have had connections with high-ranking politicians and businesspeople who have protected them. Citizens have reported suspicious foreigners or strangers and they have been told to mind their own business. People everywhere are paid to look the other way – from small businesses stealing from ­clients to the government, where members of Parliament are paid to pass laws, or not to.

Patriotism for us does not go beyond wearing the colours of our national flag.

"Unfortunately, commitment is missing in Kenya," says Ocharo. "We are not committed to the country or to each other. Saying is one thing and doing is another. We say but we do not do. We need to change policies that make us less vulnerable in terms of the way we build and construct, but also in terms of our own security."

True, this is terrorism and part of a global problem. But were we more watchful, more patriotic and more of our brothers' keepers, the loss, if any, would have been minimal. As one of my friends says: "The real terrorists are the Kenyans who took a small bribe and let these people in."

The middle class, especially, will have to drive change in Kenya. As one blogger correctly pointed out, when the public-school system fails, we take our children to private schools. When the police are corrupt and inefficient, we hire private security. We do not demand more and better from the government; we instead use our money to do what the government should be doing.

We will have to demand better for things to change in Kenya. The police officers have to be well paid, well equipped and well trained. Corrupt immigration officers will have to be fired on the spot for taking bribes and sharing the spoils with their seniors. The government must start working for its people and it must build trust among the citizens.

Corruption, without a doubt, has made this kind of terrorist act easy to carry out in Kenya.

Westgate exposed our shame. It was the most visible display of the country's failed systems, which have been allowed or tolerated for too long.

Corruption turned its head and bit us, and now it's literally bleeding us to death.

I hope it will not take another deadly attack for us to admit failure and grow up. It's not enough to have cutting-edge technology designed in Kenya, to discover oil, gas and water and to attract multibillion investments if our public institutions are not a match, and if they remain unchanged.

As long as we ignore these institutions, accept that the government and police officers are endemically corrupt, and as long as we retain the ­status quo, then these will remain the weak links of the society, and they will be our undoing.

Bertha Kang'ong'oi is a Nairobi-based Kenyan journalist