— Dr. Michael Rosenberg, president and CEO of Durham-based Health Decisions, a global clinical research firm, was among six people killed when a plane crashed into a house Monday in Gaithersburg, Md.

Rosenberg – a physician, former manager at the National Centers for Disease Control and Prevention and prolific science writer – founded the company in 1989 and garnered numerous awards for his work.

“Everyone at Health Decisions is devastated by the loss of our friend and colleague Michael Rosenberg,” Health Decisions Vice President of Clinical Affairs Patrick Phillips said in a statement. “The thoughts of the management and employees of Health Decisions go out to Dr. Rosenberg’s family as well as to the families of the other passengers."

The Embraer EMB-500/Phenom 100 twin-engine jet, which struck three houses during the fiery mid-morning crash, was registered to Sage Aviation LLC of Chapel Hill, which is owned by Rosenberg. The jet took off Monday morning from Chapel Hill on its way to Montgomery County Airpark in Maryland.

There were two others aboard the plane. Phillips did not say whether the passengers were other company employees or family members. Authorities did not release the names of the deceased.

Phillips said the company plans to announce succession plans at an appropriate time.

"We can best honor Michael by carrying on and realizing his vision of a more efficient approach to clinical development," he said. "We are committed to that goal."

The jet crashed around 10:45 a.m. in the Washington, D.C. suburb, Montgomery County Fire and Rescue Chief Steve Lohr said during a news conference.



Authorities quickly said all three people in the plane had been killed, but it took hours for fire crews to sweep the home and confirm that three people were inside. They were identified as 36-year-old Marie Gemmell and her two sons, 3-year-old Cole and a 1-month-old Devon, police said.



They were found in a second-floor bathroom. Gemmell was lying on top of her young sons in an apparent effort to shield them from the smoke and fire, said police Capt. Paul Starks. Her husband and a school-age daughter were not home and were accounted for, police said.



The fuselage of the jet crashed into the front lawn of an adjacent home, which was heavily damaged by fire, and investigators believe one of its wings, which had fuel inside, was sheared off and tore through the front of the Gemmell home, said Robert Sumwalt, a National Transportation Safety Board member. Witnesses reported seeing and hearing a secondary explosion after the plane hit the ground.



The two-story, wood-frame home was gutted. The first floor was nearly completely blown out and smoke drifted from a gaping hole in what was left of the collapsing roof. No one was injured in the adjacent homes that also had major damage.



Rosenberg was a pilot who crashed a different plane in Gaithersburg on March 1, 2010, according a government official who wasn't authorized to speak publicly and asked not to be named. Investigators are still trying to determine if Rosenberg was at the controls at the time of Monday's crash.



Fred Pedreira, 67, who lives near the crash site, said he had just returned home from the grocery store and was parking his car when he saw the jet and immediately knew something was wrong.



"This guy, when I saw him, for a fast jet with the wheels down, I said, 'I think he's coming in too low,'" Pedreira told The Associated Press. "Then he was 90 degrees - sideways - and then he went belly-up into the house and it was a ball of fire. It was terrible.



"I tell you, I got goosebumps when I saw it," Pedreira said. "I said, 'My God, those are people in that plane.'"



Emily Gradwohl, 22, who lives two doors down from the house the jet hit, was home at the time and ran outside to see what had happened.



"I heard like a loud crash, and the whole house just shook," Gradwohl told The AP. "We got jackets on, ran outside and saw one of the houses completely set on fire."



She said planes fly low over the neighborhood every day but she had never worried about a crash.



The Embrarer EMB-500/Phenom 100 twin-engine jet, which seats six people, was on approach to the airpark, which is about a mile from the crash site, officials said.

NTSB investigators recovered the cockpit voice and flight data recorders from the plane, and they were in good condition, Sumwalt said. Investigators planned to remain on the scene for up to seven days collecting evidence.

The agency planned to look into everything that could have led to the crash, including crew experience and proficiency, training and procedures, equipment performance, weather and other environmental factors such as birds, Sumwalt said.