Extensive mobilizations took place early Tuesday— authorities going by air, water and land to rescue a group underestimating the current temperatures of Cameron County ports.

Authorities say the bodies of two undocumented immigrants– an adult male and teenage boy– were found in a canal in Port Isabel at around 9 a.m. They are believed to have been trying to cross the water onto U.S. soil in the cold overnight hours.

Investigators add a third individual was transported by air to a local hospital to be treated for hypothermia.

Two others are reportedly missing, and a search is currently under way for the remaining members. Meanwhile, the preliminary cause of death appears to be hypothermia.