(PIX11/CNN) -- Four people have died after a small plane crashed into a building near Wichita's Mid-Continent Airport in southern Kansas on Thursday morning, the city's fire chief said.
There may still be some people unaccounted for and authorities are trying to determine how many people were in the building at the time, Chief Ron Blackwell said.
"The injuries are serious injuries," he said. "We're grateful a large number of people appear to have gotten out of the building."
FAA investigators are on the scene, and the National Transportation Safety Board is aware of the incident, CNN affiliate KSNW reported.
"There is a small aircraft that went into the Flight Safety Building," near Mid-Continent Airport, according to Steve Phillips, a Flight Safety International spokesman.
The plane is a Hawker Beechcraft King Air, Phillips said.
It "crashed into the roof of our training center. I have no information on how many on board," he said. "We have the manager of the training center on site, and he's making sure everyone is OK, but I don't have an answer for that."
The building is across the street from the airport, he said.
The FAA said the twin-engine plane lost an engine on takeoff and crashed into a two-story building, KSNW reported. The roof on the building's eastern side has collapsed, the station reported.
Video from KSNW showed thick smoke rising from the building at 10:20 a.m. (11:20 a.m. ET).
An official with Via Christi Health, a local hospital, told CNN affiliate KWCH that one person was transported to the medical center with critical injuries.
Ten people are unaccounted for, KSNW reported.