The mystery surrounding what happened to Malaysian Airlines flight 370 continued today with more speculation about what happened to the airliner carrying 239 passengers.

US officials believe that two communications systems aboard Malaysian Airlines flight 370 were shut down separately, 14 minutes apart - which indicates the plane did not come down because of a sudden catastrophic failure. According to investigators this indicated that the switch-off could have been a deliberate act and officials told ABC News that the two communications devices were ‘systematically shut down’.

The development related to the communications systems has the international community wondering if the disappearance could be a hijacking.

Donna Schlagheck, chair of political science of Wright State University, said there has been a decline in the number of international hijackings since Sept. 11 in part because of all the safety precautions that have been implemented. American carriers, she said, really set the standard for security regulations including not allowing anyone into the cockpit and ensuring passengers had valid passports — something two passengers on the flight did not have.

Information being gathered about the false passports combined with the news about the devices being turned off manually raises many questions, Schlagheck said. The bits and pieces that are being learned and then pieced together as part of a puzzle are starting to give a clearer picture.

“It’s beginning to look more and more like a hijacking,” she said.

If the plane was hijacked and landed in a remote location or in a foreign country, it’s odd there haven’t been any demands that have been made public.

“There are no demands that we know of,” she said. “We don’t know of any rationale.

“This is remarkably unique. I can’t think of another case where an airline went missing. I don’t think a pilot would turn off his transponder unless under great duress. There’s foul play in some form.”

There have been some domestic hijacking attempts — for example the one early in the Sochi Olympics, but that was thwarted.

“The number really has plummeted,” she said. “It’s been so long since we’ve seen a succesful one. That’s why this has been such a shock and surprise.

“My heart goes out to those families,” she said. “It’s horrifying.”