Three hunters from Florida and a dog were found dead after they got trapped in an underground cistern partially filled with water in a Texas cornfield, the Bastrop County Sheriff's Office said.

Authorities responded Wednesday morning to reports Delvys Garcia, 37, Denise Martinez, 26, and Noel Vigil-Benitez, 45, were trapped in a hole in the ground in northern Bastrop County.

There were no signs of life, and initial reports indicated "a hunting party of 3 males and 1 female ended up on foot in a corn field when one of their dogs fell into the cistern," authorities said.

Authorities believe while one of the people ended up in the cistern after "possibly" trying to rescue the dog, the other two entered it to rescue them, they said.

"A 4th member of the party went to his truck to summon assistance and call 911," the sheriff's office posted on Facebook.

"The water level of the cistern was far below the small opening of the cistern, which was at ground level, preventing anyone from escaping from the cistern, resulting in the deaths of 2 males and one female. All 3 of the decedents were Florida residents ...The dog didn't survive either," the sheriff's office posted.

An investigation to confirm "the reporting of the initial details" is underway, and an autopsy was ordered, it said.