The area around the site of remains "very volatile" because of the presence of ammonium nitrate, according to Matt Cawthon, chief deputy sheriff of McLennan County.

CNN: 12 bodies recovered, 60 unaccounted for after Texas blast

"There have been a number of entrapments, and deputies, firemen and emergency personnel have all been working to free those people, " said Robert Paris, Gordon County's chief deputy sheriff.

CNN: High winds, tornado trap Georgia residents, turn over cars

"There have been a number of entrapments and deputies, firemen and emergency personnel have all been working to free those people, " said Gordon County Chief Deputy Sheriff Robert Paris.

CNN: High winds, tornado trap Georgia residents, turn over cars

"We really have nothing new that I can tell you, other than the fact the search is continuing, " Rick Abben, chief deputy for the Black Hawk County Sheriff's Office, told reporters Monday.

CNN: STORY HIGHLIGHTS