Sonar spots what appears to be AirAsia Flight 8501

Indonesia's search and recovery agency says a sonar image appears to show the wreckage of AirAsia Flight 8501 upside down on the floor of the Java Sea, CBS News has confirmed. It is unclear whether the plane is intact.

The development comes on the fourth day of the effort to find the airliner, which crashed early Sunday. The cause isn't known, and searchers are attempting to recover the plane's "black boxes" to help investigators as they seek an explanation.

The earliest proof of the fate of AirAsia Flight 8501 emerged Tuesday from the shallow, aqua-colored waters of the Java Sea, confirming that the plane crashed with 162 people aboard in an area not far from where it dropped off radar screens.

Two days after the jet vanished, searchers began finding bodies and debris, including a life jacket, an emergency exit door and a suitcase, about 10 miles from the plane's last known coordinates.

The jet's last communication indicated the pilots were worried about bad weather. They sought permission to climb above threatening clouds but were denied because of heavy air traffic. Four minutes later, the jet disappeared from radar without issuing a distress signal.

The airliner's disappearance halfway through a two-hour flight between Surabaya, Indonesia, and Singapore triggered an international hunt for the aircraft involving dozens of planes, ships and helicopters.

Images of the debris and a bloated body shown on Indonesian television sent a spasm of anguish through the room at the airport in Surabaya, Indonesia where relatives awaited news.

Search crews had also reportedly spotted a large shadow on the seafloor, believed to be the jetliner itself.

"I know the plane has crashed, but I cannot believe my brother and his family are dead," said Ifan Joko, who lost seven relatives, three of them children, as they traveled to Singapore to ring in the new year. "We still pray they are alive."

CBS News' Allen Pizzey reports that the first six bodies were recovered relatively quickly, and then searchers began reporting more and more bodies floating in the sea 100 miles from land and a mere 6 miles from where the airliner was last in contact with air traffic control. One of the bodies was that of a flight attendant, identified by her trademark red uniform.

Images on Indonesian television showed a half-naked bloated body bobbing in the sea. Search and rescue teams were lowered on ropes from a hovering helicopter to retrieve corpses.

Rescue workers descended on ropes from a hovering helicopter to retrieve bodies. Efforts were hindered by 6-foot waves and strong winds, National Search and Rescue Director SB Supriyadi said.

Around 125 family members were planning to travel Wednesday to Pangkalan Bun to start identifying their loved ones. Body bags and coffins have been prepared at hospitals there. Dozens of elite military divers will join the massive search. They were desperate to search the water ahead of approaching rough weather.

Nearly all the passengers and crew are Indonesians, who are frequent visitors to Singapore, particularly on holidays.

Haidar Fauzie, 60, said his youngest child and only daughter, Khairunnisa Haidar, was a flight attendant who had worked with AirAsia for two years.

On learning about the crash, he struggled to console his grieving wife. They last saw their child six weeks ago, when she returned home on holiday.

"From the start, we already knew the risks associated with being a stewardess," Fauzie said. "She is beautiful and smart. It has always been her dream to fly. We couldn't have stopped her."

AirAsia group CEO Tony Fernandes, the airline's founder and public face and a constant presence in Indonesia since the tragedy started unfolding, said he planned to travel to the recovery site on Wednesday.

"I have apologized profusely for what they are going through," he said of his contact with relatives. "I am the leader of this company, and I have to take responsibility. That is why I'm here. I'm not running away from my obligations."