Seconds before a small plane crashed at a suburban Dallas airport, killing all 10 people on board, the crew commented on a problem with the left engine, federal officials said Tuesday.

The Beechcraft BE-350 King Air struggled to gain altitude before veering to the left and crashing into a hangar Sunday morning at the Addison Municipal Airport, killing a family of four, two couples and two crew members, witnesses and authorities said.

A cockpit voice recorder captured the pilots’ apparent confusion as the plane headed down the runway, Bruce Landsberg, vice chairman of the National Transportation Safety Board, said Tuesday at a news conference.

Four seconds later, the pilots indicated there was a problem with the left engine, Landsberg said. After another five seconds, three alarms sounded, warning pilots that the plane was banked too sharply to one side. The recording ended moments later, about a minute after the crew members were cleared for takeoff on their route to St. Petersburg, Florida.

Dallas County officials identified the victims as: 71-year-old Howard Hale Cassady, 52-year-old Brian Mark Ellard, 45-year-old Ornella Ellard, 15-year-old Alice Giovanna Maritato, 13-year-old Dylan Rocco Maritato, 28-year-old Matthew John Palmer, 57-year-old Gina Cunningham Thelen, 58-year-old Stephen Lee Thelen, 61-year-old John Leo Titus, and 60-year-old Mary Martha Titus.

Cassady had the same type of advanced license required of airline pilots, and was licensed to fly several types of turboprops and jets including planes made by Beechcraft, Gulfstream and Learjet, according to federal records. Palmer had a commercial pilot’s license, which would have let him work on flights with paying passengers.

The Catholic Diocese of Dallas says the Ellards were married and Ornella was the mother of Alice and Dylan Maritato.

Mary Titus, who was married to John Titus, was a league director for Tennis Competitors of Dallas, said Jinky Hicks, the group’s presiding director. She said five other members of the tennis organization were also on the plane.

Stephen Thelen was a managing director for Chicago-based real estate company JLL, working in its Dallas office, the company said. He was married to Gina Thelen.

Technical experts will review the cockpit recording in Washington and produce a transcript, which the NTSB will release along with other reports from its investigation, Landsberg said.

NTSB investigators said they don’t know yet if the captain or co-pilot was flying the plane. The board is reviewing records for both, including their recent flights. The NTSB interviewed a pilot who flew with the captain several weeks ago and reported nothing unusual, officials said.

The private plane was not required to have a flight data recorder, which tracks the performance of virtually every system on board. Federal investigators will rely on physical evidence at the crash site, video, radar information and witness accounts to determine the cause of the crash.

Officials had indicated that the plane was almost completely destroyed in the fire, but they said Tuesday that they’ll be able to analyze significant parts.

Lead NTSB investigator Jennifer Rodi said both engines and their propeller assemblies were recovered Monday and were being dissembled for closer examination. She said the main part of the fuselage was destroyed but a piece of the tail assembly “larger than I am” survived. She said investigators will try to piece together, like a puzzle, parts of the wings.

Investigators have video from four cameras, including two positioned at the end of the runway.

The NTSB said the airplane had been topped off with fuel before takeoff. The crash created a plume of thick, black smoke.

NTSB officials said they expect to wrap up their work at the crash site Wednesday afternoon. Investigators continued to scour the airport Tuesday as Addison prepares for its Independence Day fireworks display and airshow.

The damaged hangar is “well beyond the fallout area” of the Wednesday night pyrotechnics, said town spokeswoman Mary Rosenbleeth.

The event will include a message of thanks to the police and firefighters who responded to the crash and a moment of silence to recognize the victims, Rosenbleeth said.