At least 16 people are feared dead after a large hot air balloon struck a high-voltage power line, caught fire and crashed in a pasture near Lockhart, Texas, this morning, according to Texas authorities and the Federal Aviation Administration said.
The Caldwell County Sheriff's Office received a 911 call around 7:44 a.m. local time about a possible vehicle accident. The fire apparently broke out during flight in the basket portion of the hot air balloon.
"Investigators are determining the number and the identities of victims at this time," the Sheriff's Office said in a statement.
Texas Gov. Greg Abbott and his wife expressed their sympathy in a statement, saying "[We] extend our deepest condolences for all those who have been affected by today’s heartbreaking tragedy. Our thoughts and prayers are with the victims and their families, as well as the Lockhart community."
The FAA said its investigators are on their way to the crash scene and the National Transportation Safety Board, which will be in charge of the investigation, has been notified.
"The FAA and NTSB do not release the names of pilots or passengers. Names will be released by local officials after relatives have been notified," FAA spokesperson Lynn Lunsford said in a statement.
The balloon was operated by the Heart of Texas Hot Air Balloon Rides.
Today's hot air balloon crash was the deadliest in U.S. history since NTSB records began in 1964.
ABC News' Jeff Cook, Marilyn Heck and Josh Margolin contributed to this report.