KENNEDYVILLE, Md. (CBSDC/AP) — Maryland State Police say the bodies of Glen Nolt and his two teenage sons have been recovered from a large manure pit on the upper Eastern Shore.

Police said Thursday it’s not clear how the three victims became submerged in the manure pit at a dairy farm where they worked in Kennedyville. They were tentatively identified as 48-year-old Glen Nolt, of Peach Bottom, Pa., and his sons, 18-year-old Kelvin Nolt and 14-year-old Cleason Nolt.

An autopsy will determine their exact manner of death.

Police say when the three did not come home to milk their dairy cows Wednesday evening, family members became concerned and drove to the farm.

Liquid manure was pumped out of the pit overnight during the search, and the bodies were recovered early Thursday morning.

Police say they’ve found no evidence of foul play.

(TM and Copyright 2012 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2012 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)