The chicks were part of a 12,000-bird shipment left unattended in a truck at a Delaware mail distribution center. Trapped in high temperatures without food or hydration, thousands died, according to the state Department of Agriculture. The U.S. Postal Service has said it is investigating the "process breakdown" that occurred.

A Delaware animal shelter is trying to care for and rehome thousands of chicks that survived being left in a postal truck for three days. Trapped in a warm enclosure, without food and water, thousands died before they were discovered.

Delaware officials are pleading for caretakers to rehabilitate thousands of baby birds that were abandoned in a U.S.