(CNN) -- A renowned nuclear physics professor and a six-week-old baby, due to meet her grandparents for the first time, were among the 57 people killed when a plane crashed in southern Turkey early Friday, agency reports have said.
The cause of the crash, which left no survivors, is not yet known. Investigating authorities have located the plane's cockpit voice and flight data recorders, according to Turkey's civil aviation authority.
The Atlasjet Airlines' McDonnell Douglas MD-83, which left Istanbul for Isparta about 1 a.m. (22.50 GMT Thursday), went down in the mountains north of the village of Keciborlu, just as it was preparing to land, Tuncay Doganer, Atlasjet Airlines CEO, said.
He added that the pilot had radioed the tower, saying he was starting his descent. Watch CNN report on the plane crash »
But the flight, which was carrying 50 passengers and seven crew members, never arrived at Isparta airport, which is around 315 km (195 miles) southwest of Ankara, disappearing at around 2 a.m. local time.
The death toll, previously reported as 56, rose as a baby on the plane had not been counted, Turkish Pilots Association Chairman Tuna Gurel told a news conference, according to Reuters.com.
Families and friends of those on board the plane headed to airports at Istanbul and Isparta for any updates, while others tried to reach the crash site itself.
Turkish media has published the names of those onboard the plane.
The Associated Press reported that Engin Arik, a renowned nuclear physics professor at Bosporus University, Istanbul, was among those killed.
She was part of a delegation of academics who were scheduled to attend a conference at Isparta university.
Ali Ceylan said that his daughter-in-law, Melike Ceylan, 22, his six-week-old granddaughter, and his son's mother-in-law had all been killed as they returned home to Isparta, according to AP.
Ceylan said that he had been due to meet his granddaughter, who was born in Istanbul, for the first time. "We were going to see our grandchild for the first time," Ceylan said. "It's very hard for us. It's enough to make us go mad."
Ceylan's son, who serves in the police, was in a state of shock and had been given tranquilizers, he added.
According to the Dogan news agency, a transcript of the conversation between the Isparta control tower and the pilot revealed no indication of trouble.
The pilot is said to have told the tower: "Isparta tower, we are inbound" at 1:36 a.m., according to the transcript. The tower then replied: "Understood, Atlasjet. Continue to approach."
Doganer said that conditions at the time of the crash were good. "There was no rain or wind," he said. "The weather could not have been better."
He added that the flight's pilots had just returned from training and were extremely experienced. "It is not a point of issue that the pilots were sleepless or restless."
Doganer said that rescue teams had experienced problems in reaching the crash site due to the high ground. Video shows the fuselage of the plane largely intact but broken into at least three pieces, with the tail and cockpit separated from the body of the aircraft. There appeared to be no evidence of a fire.
The Anatolia news agency reported that the site, around seven miles from the airport, is strewn with debris and passengers' personal belongings. The bodies of some passengers were still strapped in their seats; elsewhere the site was littered with body parts.
The agency added that heavy machinery was being used to remove trees and allow easier access to the area.
The governor for Isparta, Semsettin Uzun, said that the site of the crash did not seem to be on the plane's usual route, the agency reported. "It is impossible to understand how the plane landed there."
Doganer said managers from the company will depart for Isparta later today with relatives of those who were onboard the plane.
Atlasjet leased the plane from Worldfocus Airlines, whose pilots were flying it, Doganer said.
Can Ertuna, of CNN affiliate station CNN Turk, said that Atlasjet was a relatively new company and that none of its flights had been involved in such a serious incident before.
In August of this year two hijackers held passengers hostage on an Atlasjet flight before giving themselves up, while in 2005 an Atlasjet plane left the runway due to wintry conditions. There were no reported injuries from either incident. E-mail to a friend
Copyright 2007 CNN. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed. Associated Press contributed to this report.