US investigators say a severe thunderstorm was the reason a tourist boat capsized on a southwest Missouri lake. The National Transportation Safety Board said weather information showed winds were two miles per hour short of hurricane force when the boat was sailing. The accident killed 17 people, including children. According to an incident report, none of the 31 passengers on board was wearing a life jacket. Investigators intend to determine if the operators followed all safety regulations at the time the tragedy struck. CGTN's Dan Williams has the story.

The collective pain and suffering following a terrible tragedy. Hundreds of mourners gathered for a late-night vigil, in the car park of the offices of Ride the Ducks in Branson.

An outpouring of emotion following events on Thursday that saw an amphibious vehicle known as a duck boat, sink, claiming the lives of 17 people. Some left candles. Others left flowers on cars believed to belong to some of the victims.

"It's just a really sad evening. I felt really bad for the families. And people who were there. But everybody came together and was taking care of each other. Try and lift each other up."

"It's obvious that people want to help. It's obvious that people want to have a sense of togetherness. And just mourning together so anything that we can all do we want to do."

RUSSELL MCKAY FRIEND OF LAKE TRAGEDY VICTIMS "It's all surreal. I am going to wake up and everything is going to be okay. And obviously it is a reality and I was heartbroken all the way down here and I could not comprehend it. But after tonight and I see this whole community coming together and pouring out their love for these two people, these two poor souls, it's healing."

Questions remain as to why the boat entered the water, as a severe thunderstorm warning had been issued some 30 minutes before the incident took place.

Nine people from a family of eleven died in the tragedy. Tia Coleman survived but she says her three children and husband were killed.

TIA COLEMAN SURVIVOR "I lost control. I didn't have anybody with me, I couldn't see anybody and I know it wasn't but it felt like I struggled for at least an hour."

DAN WILLIAMS TABLE ROCK LAKE, MISSOURI "The National Transportation Safety board say the investigation could take up to a year to complete. They are urging witnesses to share any videos or photos that may help provide further clues to how this popular excursion turned into a tragedy."

The company that operates the Duck Boats in Branson has closed the business due to the investigation and to allow the community and families to grieve. The boats date back to World War II and have been involved in other deadly incidents in other areas in recent years.

As investigators continue their work, for many here, the process of mourning has just begun. Dan Williams CGTN Table Lake Rock, Missouri.