WASHINGTON — A business jet that crashed in a neighborhood near an airport in suburban Washington, killing all three people on board and a mother and her two young sons on the ground, had slowed to the point where it nearly stalled in midair before impact, federal investigators said Tuesday.

Meanwhile, the father of the two young boys who were killed along with their mother said his family had suffered an indescribable loss. The crash sparked a fireball that gutted the family's home in Gaithersburg, Maryland, and police said Marie Gemmell died while trying to protect her sons, 3-year-old Cole and 1-month-old Devin, from the smoke and flames.

"No words can describe the enormity of our loss and sadness," Ken Gemmell said in statement emailed to The Associated Press. "We lost Marie, the love of my life and college sweetheart, and our two young, innocent and joyful sons — a loss that no person should ever endure."

Gemmell and the couple's daughter, Arabelle, were not home at the time of the crash. He asked for privacy while they grieve and try to rebuild their lives.

Shortly before impact, the plane had slowed to just over 100 mph, and its computers began sounding an alarm about an impending aerodynamic stall, National Transportation Safety Board member Robert Sumwalt said Tuesday after a preliminary review of the plane's flight data recorder.

Sumwalt said he had not listened to the cockpit voice recorder personally and did not summarize anything the pilot said before the crash. According to the data recorder and witnesses interviewed by the NTSB, the plane pitched and rolled severely in the seconds before the crash, he said. There was no indication from the data recorder that the plane had engine trouble.

There were also no reports of birds near the plane, Sumwalt said. Another pilot at the Montgomery County Airpark had reported birds standing on the runway just seconds before the crash.

All three people on board the plane were from North Carolina and worked in the health care field, including the pilot, 66-year-old Dr. Michael Rosenberg, who had also been involved in a minor crash at the same airport in 2010, officials said.

Police tentatively identified the other people aboard the plane as David Hartman, 52, and Chijioke Ogbuka, 31. Hartman worked for a clinical pharmacology consulting firm, Nuventra Pharma Sciences, and its CEO said in a statement that the company was deeply saddened by the loss. Rosenberg was the founder and CEO of a company called Health Decisions, and the company said in a statement Tuesday that Ogbuka also worked there.

In 911 calls released by authorities overnight, shock and alarm is evident in the callers' voices.

"I just saw a jet hit a house! The house is on fire," one man said. "When he came in on final (approach), it flamed out and he went straight down into that house."

Two other houses were damaged in the crash, but they were empty and no one else was hurt.

Montgomery County Executive Isiah Leggett said Tuesday that the county would review policies and procedures at the airport, including the paths of approach to the runways.

"When you have an incident like this, it calls into question the safety," Leggett said during an appearance on NewsChannel 8, a local cable channel. "We certainly owe it to the community to go back and check and evaluate, and we will do that."

Including Monday's crash, there have been 30 accidents at the airport in the past 31 years, according to NTSB records. Before Monday, the most recent fatal crash was in 1990, and most of the recent crashes involved minor or no injuries.

Steve Hedges, a spokesman for the Aircraft Owners and Pilots Association and a pilot who knows the Gaithersburg airport well, said many of the recent incidents would be better characterized as hard landings, and some occurred during flight instruction.

"That's not unusual in an instructional environment. Things happen when people are learning how to fly," Hedges said Tuesday. "I think it's a very safe airport, actually."

The previous crash involving Rosenberg occurred in 2010 and involved a different plane that began to drift after it landed. The plane briefly became airborne again before crashing into the runway. Asked whether he was hurt, Rosenberg said, "only his pride," according to NTSB documents.

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In the headline of a previous version of this story, it incorrectly said the plane stalled. The NTSB says the plane nearly stalled.