These students are lucky to be alive.

ABC News reports.

Arkansas College Students Went Into ‘Survival Mode’ to Survive Nearly 30 Hours Trapped in Cave

One of three Arkansas State University students who was rescued Thursday after being trapped in a cave for nearly 30 hours said the trio went into “survival mode” to make it out alive.

“Initially we were panicked about not being able to make it out but after that we got into survival mode,” Casey Sherwood, 25, told ABC News. “We got ourselves hunkered down and we decided to wait it out.”

Sherwood, a rising senior at Arkansas State, was leading two incoming, freshman foreign exchange students from Japan on a spelunking expedition in the Batesville cave system near Cushman on Wednesday when they became trapped.

The two foreign exchange students were identified by the university as Daiki Itoh, 19, from Hiratsuka, Kanagawa, and Daisuke Takagi, 18, from Kawagoe, Hyogo.

It was Sherwood’s wife, Katherine Sherwood, who alerted authorities that the trio were missing late Wednesday. Emergency personnel responded to the scene around 1:45 a.m. Thursday.

Firefighters and cave experts from a local college entered the cave, known as Blowing Cave, a deep and dark cavern of which less than two miles is officially mapped.

Sherwood, of Jonesboro, Arkansas, said the routine he and his fellow students established to call for help was what ultimately led to their rescue.