BRUSSELS — Six-year-old Carlton Kahindi took the tea candle in his tiny hand and gently placed it on the makeshift memorial to victims of Belgium’s attacks.

Though he could barely see from beneath a stocking cap, he knew his actions had meaning. That’s why he was really careful.

“It’s for the people who went to heaven,” he said.

Thousands of people came to Brussels’ central square on Wednesday, determined to defy extremists who would have them cower in fear. The city got back to work, if not back to normal.

Many of those laying flowers, lighting candles and scrawling messages of peace in chalk were children brought by parents who were seeking to explain that something terrible had happened. They wanted them to understand.

“I want him to still have faith in humanity,” said Carlton’s mother, Carole Kahindi.

Defiance and fear mingled in the minds of residents coming to terms with the violence that they had long expected, but had hoped wouldn’t come.

“You can’t protect yourself against terrorism. Are you going to stay at home today? Tomorrow? The day after tomorrow?” asked Dirk Verstraeten, 53, who was catching a bus to work. “Life must go on.”

Jean and Anne-Marie Materielle were among only two dozen or so tourists admiring the gilded gothic facades of Brussels’ Grand Place. The pair from central France arrived in Brussels on Tuesday, arriving in the Molenbeek neighborhood only hours after the three bombs went off in the Brussels airport and subway.

Both said they’d gotten an earful from a local businessman who was devastated that his neighborhood — a favored locale for several of those who attacked Paris on Nov. 13 — was once again at the center of world attention.

“He wasn’t happy,” Jean said.

A platoon of soldiers is now standing guard outside the city’s central train station. There’s only a trickle of tourists flowing through Brussels’ gothic Grand Place and gardeners at Brussels’ 18th-century Warandepark are checking each trash can extra carefully.

A line swelled outside the central train station in Brussels as travelers lined up to get their bags checked. Soldiers stood guard every few feet as half a dozen military trucks idled nearby.

The mood on the street was jittery. Several metro stations were still closed, roads were snarled with traffic. Sirens repeatedly wailed.

Joggers ran loops and dog walkers chatted in Brussels’ Warandepark, across from the country’s parliament. But the gardeners on duty said the atmosphere was different.

“It was a black day. A very black day,” said Jean-Marie Vrebos, a 58-year-old cleaning the park’s playground. “We should punish those who commit terrorism. We don’t deserve terror.

“We should punish them, grab them” — he said as he yanked a piece of trash off the ground with a clasper — “and bring them to justice.”

His colleague Kevin Engels, 24, said, “behaviors have changed. Even our bosses seem stressed. They asked us to empty all the trash cans. We pay close attention to everything.”

“And you can hear the sirens,” he added as an emergency vehicle blared its way down the road.

Yet everywhere around the city people just insist that this won’t break them, even though it’s impossible to put it out of mind.

“I am not afraid, because terrorists want you to be afraid. That’s the thing: they win if we get afraid to leave home,” said student Alexandra Cyran.

“But today, when I was walking to school, I was looking at the people and I was thinking: does he have a bomb? Is this person OK?”