An Asiana Airlines flight has crashed while landing at San Francisco airport, a federal aviation official said. It was not immediately known whether there were any injuries.

An investigation was under way today after a Boeing 787 jet on a test flight over Texas made an emergency landing when smoke was detected in the main cabin.

A software engineer , furious with the US Internal Revenue Service, crashed his small plane into an office building housing nearly 200 federal tax employees today, officials said.