Haiti’s massive street celebration that normally would have closed out its annual Mardi Gras festivities turned into a solemn affair Tuesday as thousands of saddened revelers joined their country’s leaders in a silent march to honor more than a dozen people killed in a carnival float accident earlier in the day.

Wearing white and holding candles, the crowd gathered around the scene of the tragedy on the Champ de Mars, the vast network of public squares where the three-day pre-Lenten national carnival kicked off Sunday.

Amid the colorfully decorated viewing stands, Haitians stood in silence remembering the victims. The tragedy happened when a sound truck with towering speakers transporting popular Haitian hip hop band Barikad Crew hit a power line at 2:48 a.m.

Sixteen people were killed and 78 injured, according to government officials.

“It’s like a carnival but without music,” said Gregory Saba, president of the National Carnival Committee. “There is nothing like carnival in Haiti. It is the most enjoyable moment for the people. So when something like this happens, it is sad, really sad.”

Saba called it an accident. In a televised speech, Prime Minister Evans Paul echoed Saba’s sentiments, saying that although a commission had been put in place to investigate the tragedy, “it is clear what happened was an accident.”

Nevertheless, Paul declared all carnival festivities canceled throughout the country, and a national period of mourning from Wednesday to Saturday when a national funeral will be held for the victims.

“We cannot dance, we cannot celebrate on their corpses,” Paul said. “But we can show them our respect.”

For his part, President Michel Martelly tweeted out sympathies to the families of the victims. A former singer and king of carnival who became president, he was taking the tragedy really hard, his friends said.

For Haitians, the three-day respite is a chance to replace strife with boisterous joy and masked celebrations.

Martelly’s children — three of whom have carnival songs this year — had already traveled through the crowds without incident, as did nine other floats before Barikad Crew began making its way down the tightly packed, narrow route. The float had just passed in front of Martelly, who was viewing the celebrations, and first lady Sophia Martelly, who was at a separate medical stand.

The float was headed toward the Rex Theater on Rue Capois, a few feet from the Hotel Le Plaza on its way to the national soccer stadium. Music was blasting and a shirtless Fantom, one of the six-member group’s singers, was standing atop a towering speaker with a microphone in his right hand. His head was turned to the side, away from the oncoming power line, as seen on video footage.

“It all happened suddenly and quickly,” said Christian Lemaine, 23, who was walking next to the float through the packed crowd. “I heard a loud noise, like an electric explosion, felt a quick electrocution through my body, particularly through my elbows and I automatically ducked away.”

Suddenly, the music and float stopped. Chaos broke out as screaming fans ran.

Bricks, one of Barikad’s artists, screamed for help, asking for paramedics.

“He was yelling, ‘Fantom! Fantom!” Lemaine said. “That’s when we started understanding that someone on the float had been severely electrocuted.”

Youri Chevry, the group’s manager, said Fantom thought he had cleared all of the power lines.

“Our float was high and he was standing up. He was talking and from the video footage I saw, his head hit the power line,” said Chevry, who was also following the float on foot and looked up when he heard the explosion.

As the electricity struck Fantom’s microphone in a flashing spark, the crowds scattered.

Doctors at the state hospital where Fantom was transported, were surprised that the singer didn’t suffer a heart attack or die after coming in contact with the power line, Chevry said.

“They are holding him for 24 hours to see what happens,” Chevry said. “They think he will recover quickly.”

Sophia Martelly, who visited the singer Tuesday, said he was awake and joking, asking to go home.

“He was extremely lucky,” she said.

Martelly’s team of 22 doctors and 10 nurses were the first responders on the scene, just a few feet from where the accident happened.

“There was a commotion and people were running toward me screaming, ‘power, power,’” she told the Miami Herald. “I thought they were going toward a band, but then I saw everybody looking back.”

With the accident occurring not far from the first lady’s medical stand, doctors and nurses were able to quickly respond. Fatom was treated on the scene, said Sophia Martelly, who has set up the emergency medical response since her husband hosted his first carnival as president in 2011 in Les Cayes.

“We had people all over, all over,” Sophia Martelly said.

When they ran out of beds, patients were laid on mats and stretches on the carnival route.

“It was all happening so quick, we didn’t even time to register people,” she said.

Martelly said she envisioned the medical stand would treat lacerations, minor cuts and dehydration. Tuesday’s tragedy, she said, was the last thing she expected.

“There are just no words to describe it. We still don’t know exactly what happened,” she said, acknowledging that the victims list could have been higher. “We were the closest ones to the scene and we were able to respond, very, very quickly. The ambulances came super fast.”

Lemaine agreed, saying he witnessed a great effort from “the rescue team to react quickly and effectively to save as many lives as possible. ‎The fact that the emergency center was so close to where the accident happened really helped.”

After the accident, many questioned the circumstances that led up to it. Lemaine said he doesn’t know whether there was anyone on the float, as is normal, to clear power lines using a long wooden, Y-shaped stick.

Saba, the carnival head, said the accident had nothing to do with dangling power lines, which have long been an issue in Haiti.

“He was so excited to see the fans that he stood up, and even the driver slowed down,” he said. “Usually, they never stand up. He thought he had passed all of the power lines but the driver hadn’t passed the third one.”

It was the second major tragedy to hit Barikad Crew, which lost three members in a 2008 traffic accident in Haiti.

“We want for all fans to know we are alive. Fantom is alive and he’s in the hospital,” Chevry said. “We are asking everyone to pray for him.”