U.S. military sources tell Fox News that a Marine CH-53 Sea Stallion helicopter crashed in southern Afghanistan on Thursday.
Six American Marines who were members of the International Security Assistance Force were killed in the crash, however, the military is still gathering details about the incident.
No enemy activity was reported in the area at the time of the crash, Fox News reported. It is not yet clear what caused the chopper to go down.
The ISAF has secured the crash site.