Grassley, meanwhile, is demanding that the White House counsel make public details of her internal inquiry in addition to an independent investigation of White House staffers.

CNN: STORY HIGHLIGHTS

Grassley is demanding that, in addition to an independent investigation of White House staffers, the White House counsel make public details of her internal inquiry.

CNN: Senators criticize military briefing on Colombia scandal

"We are working closely with the Turkish national police to make a full assessment of the damage and the casualties, and to begin an investigation, " she said.

CNN: Suicide bomber kills one outside U.S. Embassy in Turkey

The crash caused an intense fire that incinerated much of the plane, something that will make the investigation difficult, Duprie said.

CNN: Florida plane crash survivor: 'God is good'