Updated at 8:51 p.m. ET
BIRMINGHAM, Ala. Investigators seeking the cause of recovered cockpit-voice and flight-data recorders Thursday, the National Transportation Safety Board said.
Investigators had been unable to retrieve the black boxes earlier because the tail section of the wreck was still smoldering.
The crash killed the two pilots on board and scattering wreckage over a wide rural area moments after witnesses heard the massive jet coming in at treetop level.
Kevin Hiatt, a former Delta pilot who is now CEO of the Flight Safety Foundation, has flown into Birmingham numerous times. Of the steep drop in altitude before the crash, Hiatt told CBS News: "It was a about a 7,000-foot loss of altitude in about two minutes or about 3,500 feet per minute. On an approach, sometimes we are doing what's called a "slam dunk." And that means that you're losing a lot of altitude very quickly to get you into the realm of being on the approach to prepare for the landing. That means getting you to an altitude where you can start to transition with your gear and flaps to come on down and land the aircraft."
People living near the airfield reported seeing flames coming from the aircraft and hearing its engines struggle in the final moments before impact.
"It was on fire before it hit," said Jerome Sanders, who lives directly across from the runway.
The plane, an A300 that had departed from Louisville, Ky., went down around daybreak about a half-mile from Birmingham-Shuttlesworth Airport. It broke into several pieces and caught fire. The pilot and co-pilot were the only people aboard.
Meanwhile, the Jefferson County, Ala., medical examiner on Thursday night identified the victims as Capt. Cerea Beal, Jr., 58, of Matthews, N.C. and First Officer Shanda Fleming, 37, of Lynchburg, Tenn.
Lynchburg residents say Fanning loved flying, and began piloting planes as a teenager.
Wes Fanning, who told The Associated Press he was Fanning's brother-in-law, said UPS representatives were with the family.
An ex-Marine, Beal had been with UPS since 1990. Fanning had worked with the company since 2006.
UPS issued a statement about the pilots that read: "The UPS Family Assistance Team is providing support to the crew members' families during this difficult time. The entire UPS family sends our condolences and will keep the Beal and Fanning families in our thoughts and prayers."
Weather conditions at the time of Wednesday's crash were rainy with low clouds.
Toni Herrera-Bast, a spokeswoman for the city's airport authority, said the crash did not affect airport operations, but it knocked down power lines.
UPS spokesman Jeff Wafford said the jet was carrying a variety of cargo. He did not elaborate.
The field where the crash happened had a neighborhood in it until several years ago, when airport officials began buying up and then razing the houses to clear the area near the end of the runway.
But such offers, which began in 1986, weren't made on some of the nearby houses, including that of Cornelius and Barbara Benson, who live in a two-story, split-foyer home just a short walk from the crash site.
"Hopefully we can get out of here now," said Cornelius Benson.
Chunks of riveted metal that appeared to be from the plane landed in the Bensons' yard.
Barbara Benson said she was awakened by a tremendous boom and "saw a big red flash" through her bedroom window.
As day broke, the two were able to see that the tops of trees around their property had been knocked down and they were missing a piece of their back deck.
Cornelius Benson said planes routinely fly so low over his house that a few years ago, the airport authority sent crews to trim treetops.
The planes come close enough that Barbara Benson has sometimes been able to "to wave at the captains as they pass."
Ryan Wimbleduff, who lives just across the street from the airport property, said the crash shook his house violently. Standing in his driveway, he and his mother could see the burning wreckage.
"I ran outside and it looked like the sun was coming up because of the fire on the hill," he said. "Balls of fire were rolling toward us."
Sharon Wilson, who also lives near the airport, said she was in bed before dawn when she heard what sounded like engines sputtering as the plane went over her house.
James Giles said the plane missed his home by a couple of hundred yards, judging from tree damage and debris. He was at work at the time but said it was clear from the scene that the plane was attempting to land on the north-south runway that is typically used by much smaller aircraft. Large planes such as the A300 typically aim for the bigger east-west runway, he said.
"They were just trying to get to a landing spot, anywhere," he said.
The plane was built in 2003 and had logged about 11,000 flight hours over 6,800 flights, Airbus said in a news release.
The A300, Airbus' first plane, began flying in 1972. Airbus quit building them in 2007 after making a total of 816 A300 and A310s. The model was retired from U.S. passenger service in 2009.
Wednesday's crash comes nearly three years after another UPS cargo plane crashed in the United Arab Emirates, just outside Dubai. Both pilots were killed.
Authorities there blamed the Sept. 3, 2010, crash on the jet's load of 80,000 to 90,000 lithium batteries, which are sensitive to temperature. Investigators determined that a fire probably began in the cargo containing the batteries.