Three people -- including one firefighter -- were injured when a fire broke out at Trump Tower in New York City on Monday, officials said.

A small electrical fire started in the cooling tower on the roof of the Fifth Avenue high-rise, which was built by President Trump when he was a businessman, just before 7 a.m., the FDNY said. The flames were put out about an hour later.

More than 126 firefighters responded to the scene. Video footage showed several firefighters on the roof while smoke spewed forth.

The building was not evacuated. A firefighter sustained minor injuries when debris fell on him. The building's engineer and another person suffered injuries that were not life threatening. They were treated at the scene and refused further medical attention.

Trump's son, Eric Trump, thanked the New York City fire department for the "incredible job" they did containing the flames before the fire spread.

"There was a small electrical fire in a cooling tower on the roof of Trump Tower," Trump tweeted. "The New York Fire Department was here within minutes and did an incredible job. The men and women of the #FDNY are true heroes and deserve our most sincere thanks and praise!"

Trump Tower has been protected by heavy security presence since President Trump was elected in November 2016. The building houses both businesses and luxury apartments.

First lady Melania Trump and their son Barron lived in the New York City residence for the first few months of Trump’s presidency before officially moving into the White House.