A flight from Philadelphia International Airport with 56 people aboard made an emergency landing in Houston Monday night after its nose gear failed to deploy.

Only one passenger required treatment for what officials called a minor injury.

American Airlines Flight 1825, operated by US Airways, made the landing at Houston's George Bush Intercontinental Airport about 9:30 p.m. (10:30 p.m. Philadelphia time), according to airport and airline officials.

While preparing for landing in Houston, the pilot noticed the landing gear had not deployed and circled the traffic-control tower for visual confirmation that the gear wasn't coming down, airport spokesman Bill Begley said.

The pilot decided to make an emergency landing. Passengers exited the plane on the tarmac via aircraft slides, American Airlines said in a statement.

There were 52 passengers and four crew members on board the Embraer 190 jet, the airline said.

An investigation is underway to determine why nose gear failed to deploy.