Lockhart, United States: Sixteen people were killed when a hot air balloon crashed in a fiery blaze on a rural field in central Texas, authorities told local media Saturday, one of the deadliest such accidents in history.

The balloon burst into flames and plummeted to earth soon after dawn outside the town of Lockhart, some 30 miles (50 kilometres) south of Austin, Lynn Lunsford of the Federal Aviation Administration (FAA) said in a statement.

‘When the Emergency Responders and the Sheriff’s Office arrived on the scene, it was apparent that the reported fire was the basket portion of a hot air balloon,’ the Caldwell County Sheriff’s Office said in a statement posted to Twitter.

The Texas Department of Public Safety confirmed that the 16 people onboard had died, according to the Austin American-Statesman and other US media.

Reporters at the scene, who gathered on a country road where passersby stopped to gawk in the searing Texas heat, were kept at arm’s length from the actual crash.

Local residents speculated that the balloon had struck a power line that runs prominently across the field.

‘I didn’t see the balloon hit. I just heard the popping. And I heard the popping, and then the next thing I knew is the fireball went up,’ Margaret Wylie, a 66-year-old who lives nearby and witnessed the crash, told broadcaster TWC News Austin.

FAA investigators were traveling to the site, Lunsford said, with the National Transportation Safety Board was taking charge of the probe.

The FBI’s evidence response team in the city of San Antonio was asked to assist in the investigation, NTSB lead investigator Erik Grosof said.

Texas Governor Greg Abbott offered condolences to those affected by the crash.

‘Our thoughts and prayers are with the victims and their families, as well as the Lockhart community,’ he said in a statement.

‘Big ball of flames’

A photo posted on social media apparently depicting the accident showed a balloon in the air with huge flames spurting underneath.

‘It was a fire, a big ball of flames. You could tell nothing of what it was,’ Don Schulle told local TV station KYTX, standing on the edge of the field where the balloon crashed.

The 16 deaths make the balloon accident the deadliest on record in the United States. Previously, the highest number of fatalities in a single US hot air balloon crash was six.

In 2013, a sunrise hot air balloon flight over Egypt’s ancient temple city of Luxor caught fire and crashed, killing 19 tourists. The pilot and one other tourist survived by jumping from the balloon.

However hot air balloon crashes are rare in the United States. The NTSB investigated 760 such accidents between 1964 and 2013. Of those, 67 were fatal.

Three people died in May 2014 during an air balloon festival in Virginia when a balloon hit a power line and burst into flames while landing.

Hot air balloons use propane gas to heat air that keeps them afloat. They are regulated by the FAA, which requires balloon pilots to be certified and for balloons to have air worthiness certificates.

The FAA inspects the balloons used for commercial ventures after 100 hours of flight time or at least once a year.