-- Texas authorities and the Federal Aviation Administration are still piecing together the details of a deadly hot air balloon crash that killed 16 people on Saturday morning near Lockhart, Texas. The balloon struck a high-voltage power line, caught fire and crashed in a pasture.
Federal investigators are still determining whether the fire occurred before or after the balloon hit the power lines.
"We're looking at the power lines, it's pretty suspicious the balloon ending up right below the power lines," said Sumwalt. "Power line strikes are a factor in about 15 percent of ballooning accidents."
Authorities said there were reports of fog on Saturday.
The FBI evidence response team found 14 cellphones, one iPad and three cameras among the wreckage. Sumwalt said he is hoping the investigators will be able to gather some information from the devices, which could have captured the final moments of the flight.
Witnesses described seeing the balloon engulfed in flames.
"You could see that they were just stuck, the flames that were in the balloon, they were coming on and going off," witness Erika Gonzalez said.
"I went outside and I saw a flame at the highline," according to Horace Miller. "I went on down there and there was this basket underneath the highline burning."
Federal authorities won't publicly name the pilot, but friends have identified him as 49-year-old Skip Nichols.
"He held a commercial pilot certificate with a balloon rating," Sumwalt said. "He did not have any other ratings to fly airplanes or helicopters, only balloons."
Among the passengers on board was newlywed couple Matt and Sunday Rowan, according to a family member. The San Antonio couple, both 34, had texted family and posted pictures of the ride on social media.
Sunday's mother, Janis Stewart, said she realized she lost her daughter and son-in-law when she stopped receiving text messages and seeing posts on social media. "Knowing that they were on that balloon, I saw pictures of the balloon, it was the same one that they were on, my only conclusion when I heard that there were no survivors is that we had lost her and Matt," she said.
The family of passengers Joe and Tresa Shafer also feared they had lost their loved ones. A family member told ABC News the couple cherished spending time with their kids and grandchildren.
"Anytime we defy gravity there's a certain risk associated with that and unfortunately the tragic events of Saturday show that some times that risk is greater than we're willing to accept," said Sumwalt.
The tragedy in Texas on Saturday was the deadliest hot air balloon crash in the U.S. since federal authorities started keeping records. The NTSB has called for more regulation of the hot air balloon industry.