The Drug Enforcement Administration extended an apology to a University of California engineering student who was locked in a holding cell for more than four days and forgotten about. ...... The student drank his own urine in desperation and attempted to kill himself, before agents returned four days later and found him, he said in a news conference covered by NBC and other outlets. "I am deeply troubled by the incident that occurred here last week," DEA San Diego Acting Special Agent in Charge William R. Sherman said in a statement provided to Yahoo News. "I extend my deepest apologies the young man and want to express that this event is not indicative of the high standards that I hold my employees to. I have personally ordered an extensive review of our policies and procedures." An earlier statement from the San Diego DEA office was less contrite, with spokeswoman Amy Roderick saying that the student was caught in a drug raid because "he was at the house, by his own admission, to get high with his friends." Daniel Chong, 24, said that he was taken to the local DEA office after he was caught in a drug raid where he was smoking marijuana on April 20. The agents didn't charge him criminally and even told him they would drive him home, but apparently forgot about him in a tiny holding cell, where he languished for days without food, water, or a bathroom. Chong says he finally gave up on screaming for help, and eventually tried to kill himself with the glass from his spectacles and drank his own urine, sure he would die there. A DEA agent discovered him days later and quickly called an ambulance which drove him to the hospital, where he spent three days in intensive care because of his near-failing kidneys, he said. Chong's lawyer, Gene Iredale, tells Yahoo News his client could hear agents talking and other sounds from his cell, but no one answered his screams. He said Chong was handcuffed. "I believe it was, at best, inconceivably indifferent negligence" Iredale said of the incident. "I have dealt with cases in which police have abused citizens, but I've never seen anything as egregious as this." Iredale plans to file a civil suit as soon as possible. San Diego DEA agent Amy Roderick said earlier on Wednesday in a statement to Yahoo News that Chong was caught in a home raid on a "suspected MDMA distribution organization" that also netted several weapons, 18,000 MDMA ("ecstasy") pills, marijuana, and hallucinogenic mushrooms. "The individual in question was at the house, by his own admission, to get high with his friends," she wrote. She admitted in the statement that Chong was "accidentally" left in one of the holding rooms, while eight other suspects were either released or transfered to the county jail. Chong also told agents he ate a packet of white powder he found in his cell, which turned out to be meth. "DEA plans to thoroughly review both the events and detention procedures on April 21st  and after," Roderick wrote.