There were no survivors after a hot-air balloon carrying at least 16 people caught fire and crashed in the US state of Texas, according to local authorities.
The Federal Aviation Administration (FAA) also confirmed Saturday's crash, which occurred outside the city of Austin on a clear day.
Emergency responders in Texas said the fire had hit the hot air balloon's basket portion.
"Right now, we have a number of fatalities," a National Transportation Safety Board (NTSB) spokesman said from the scene, adding that an FBI team was being dispatched to help in evidence-gathering.
The NTSB offered no details on what may have caused the accident. It said it believed the balloon belonged to a tour company.
The crash of the balloon is the deadliest on record in the western hemisphere, according to Jeff Chatterton, a spokesman for the Balloon Federation of North America.
"There are thousands of balloons that go up every year," he said. "This is unspeakably tragic but it is rather unique."
More than 150 commercial hot-air balloon companies are in operation in North America, Chatterton said.
The sheriff's office said it was working to determine the identities of those aboard.
The accident occurred about three years after 19 people, mostly Asian and European tourists, were killed in a hot-air balloon crash in Luxor, Egypt.
A year before that incident, a hot-air balloon burst into flames and crashed in New Zealand, killing all 11 people on board in the country's worst air accident in more than three decades.