 She said that when staff went to look for their colleague , where he was thought to be  they had to retreat due to further volcanic activity and the track being impassable with fallen trees and ash.
<fluency>  She said that when staff went to look for their colleague , where he was thought to be  they had to retreat due to further volcanic activity and the track being impassable with fallen trees and ash.
 She said that when staff went to look for their colleague where he was thought to be they had to retreat due to further volcanic activity and the track being impassable with fallen trees and ash.