Twitter exploded in reaction to the real-time broadcasting flub, while video of the graphic incident briefly found its way onto YouTube, as a badly shaken senior Fox News anchorman apologized profusely.

 “We really messed up and we’re all very sorry,” said anchorman Shephard Smith, who told viewers that a five-second delay in the live feed ought to have enabled the graphic scene to be stopped before going on air.

 “That didn’t belong on TV,” Smith said. “We took every precaution we knew how to take to keep that from being on TV. And I personally apologize to you that that happened... That won’t happen again on my watch.”  It was not immediately known whether the unidentified suspect was alive or dead, but that did not discourage Twitter users from proclaiming that Fox News, part of Rupert Murdoch’s media empire, had telecast a “suicide” as it happened.

The Fox affiliate in Phoenix said police had pursued the carjacking suspect at speeds of up to 110 miles (175 kilometers) per hour for more than an hour, mostly on westbound Interstate 10.

From the expressway, the red Dodge Caliber hatchback veered onto dusty back roads in the vicinity of Salome, a town west of Phoenix.

The driver, wearing an American football jersey, was then seen abandoning the car and fleeing on foot, with no police officers visible in the tightly framed aerial shot.

“He’s looking kind of erratic, isn’t he?... It’s always possible the guy could be on something,” said Smith in a running commentary, unaware of what was about to happen.

Turning into some bushes, the suspect then pulled out a handgun, put it to his right temple and collapsed.

On air, Smith shouted “get off it! get off it!” in a plea to his studio colleagues to halt the live feed.

In the hours that followed, YouTube scrambled to delete the video almost as quickly as its users were posting it, saying it violated its terms of service.

On Twitter, meanwhile, one viewer exclaimed: “Cannot believe i just watched a live car chase for an hour and then all the sudden watched him shoot himself in the head.. Crazy.”  Live telecasts of car chases are a longtime staple of US television news, with the 1994 pursuit of disgraced football star and actor O.J. Simpson in Los Angeles a classic of the genre.

The live broadcast of the car chase and bloody aftermath drew criticism from a number of media observers.

“There is simply no excuse for this. It is sensationalism to carry it in the first place,” said Al Tompkins of the Florida-based Poynter institute on the journalism school’s website.

“Whatever local reasons there might be to carry it do not apply to a national audience,” Tompkins said.

“And yet this happens time and again and has for more than a decade and a half,” he said. “Each time, TV stations apologize while enjoying a temporary ratings bump.”  “I am not sure there is an explanation for this kind of gatekeeping ineptitude,” said Baltimore Sun television critic David Zurawik in a blog on the newspaper’s website.