New York City fire officials say a fire in Trump Tower's heating and air conditioning system injured two people and caused smoke to billow from the roof.

The Fire Department of New York said the fire started at around 7 a.m. ET Monday at the building, which contains U.S. President Donald Trump's home and business offices.

Fire officials said a civilian was treated for serious injuries and a firefighter was treated for minor injuries. It took about an hour to put out the fire at the building, which is located on Fifth Avenue in Manhattan.

The president's son Eric tweeted his thanks to firefighters for doing "an incredible job."