The National Transportation Safety Board is investigating the fatal power boat accident that killed five people and injured nine off Florida's east coast.
"We are looking at the man, the machine and the environment," NTSB member Deborah A.P. Hersman said at a Monday afternoon briefing.
Hersman revealed that there were 14 people in the 22-foot power boat that crashed into the rear of the tug at about 7 p.m. Sunday near Palm Valley in St. Johns County, about 25 miles southeast of Jacksonville. Investigators had earlier said 12 people were aboard the boat.
The NTSB is working with the Florida Fish and Wildlife Conservation Commission, the U.S. Coast Guard and the St. Johns County Sheriff's Office.
NTSB investigators will look over evidence collected by local authorities and interview witnesses and crash survivors.
Hersman said the NTSB doesn't investigate many boating accidents, but said this case with five fatalities and nine injuries met the agency's criteria for a serious accident that warranted special attention.
"Our investigations are very comprehensive and we leave no stone unturned," she said.
The primary focus is to learn lessons that can be applied to prevent future accidents, Hersman said.
Six accident victims were being treated at Shands Jacksonville hospital. Two were in critical condition Monday, one was in serious condition and three were in fair condition. Authorities have not said where the other three victims were being treated.
Debi Davis and her husband Herb, who live nearby, watched afterward as rescuers pulled the victims from a narrow section of the waterway.
"You could hear screaming as they pulled one woman out on a gurney board," Davis said.
Visibility was clear when the accident occurred, but Davis said she was surprised by the amount of damage and the death toll.
"I don't know how they could have missed it, the tug is hard to miss," she said.
Davis said that the waterway is usually busy on Sundays.
The victims' names have not been released. Hill said investigators were still trying to verify their identities.
"Investigators are looking at anything that may have caused this," Hill said, including the speed and capacity of the boat, lighting conditions and whether alcohol may have been a factor.
Investigators have been tightlipped about what they have learned.
Chuck Mulligan, a spokesman for the St. Johns County Sheriff's Office, said deputies and paramedics had to scramble to find construction material to build a bridge to the victims on the pier under construction.
"They did this knowing time was critical and once medical treatment was given those patients, they would be need to be brought off the crash site and on the makeshift dock," Mulligan said.