The U.S. Justice Department will be paying $4.1 million to 25-year-old Daniel Chong, for leaving him in a windowless Drug Enforcement Administration (DEA) cell, unmonitored for more than four days without food and water. With the money, Chong plans to buy a house for his parents.

"This was a mistake of unbelievable and unimaginable proportions," said Julia Yoo, one of Chong's attorneys.

An economics student at the University of California, San Diego, Chong said that he drank his own urine to stay alive amid fears that agents were trying to poison him with gases through vents. He also attempted to carve a farewell message to his mom on his arm.

"It sounded like it was an accident -- a really, really bad, horrible accident," Chong said.

Earlier, Eugene Iredale, one of the attorneys for Chong, threatened to file a lawsuit against the DEA.

"What happened to Daniel Chong should not happen to any human being," Iredale said.

Chong was a 23-year-old engineering student when he was taken into custody on April 21, 2012 during a drug raid by the DEA.

A multiagency narcotics task force, including state agents, detained nine people on the whole and seized about 8,000 ecstasy pills, marijuana, prescription medications, hallucinogenic mushrooms, several guns and thousands of rounds of ammunition from one of his friend's house in University City.

Iredale admitted that Chong was there to consume marijuana.

Darin Reis, a San Diego police officer told him that he will not be charged and said, 'Hang tight, we'll come get you in a minute.'

But the door to the 5-by-10-foot cell did not reopen for four and a half days.

Chong said that he began to hallucinate on the third day in the cell at the DEA's San Diego headquarters. He urinated on a metal bench and drank his own urine hoping that it would help him stay alive, and placed his blanket, pants and shoes on top of one another on a bench to reach a fire sprinkler, in an attempt to unlock the cuffs.

"I had to do what I had to do to survive," Chong said. "It's so inconceivable. You keep doubting they would forget you."

He also broke his eyeglasses and used one of the broken sharp glass pieces to carve, 'Sorry Mom' on to his arm. He could only carve out an 'S.'

Chong's ordeal in the cell finally came to an end on April 25, 2012 when he slid his shoelace under the door and screamed his lungs out to grab attention. Immediately five or six people opened the steel door and found the handcuffed student severely dehydrated and covered in his feces in the cell.

 "All I wanted was my sanity," Chong said. "I wasn't making any sense."

Because of his confinement in a windowless cell for several days, Chong was hospitalized for five days including three days in ICU for dehydration, kidney failure, cramps and a perforated esophagus. He also lost 15 pounds and suffered from severe post-traumatic stress disorder.

"He's the strongest person I have ever met," Yoo said. "As a result of his case, it's one of the primary reasons the DEA placed a nationwide policy that calls on each agent at satellite offices to check on the well-being of prisoners in their cells on a daily basis."

Currently, Chong is completing his undergraduate degree at the university.

"He changed his major from engineering to economics and wants to finish school, pursue his career and help take care of his mother," Yoo said.