Delta Flight 253 was carrying 278 people, and President Obama immediately ordered additional security measures in all of the nation's airports. The attacker was reportedly a Nigerian citizen, and claimed allegiance to Al-Quaeda.
He ignited a "powdery substance" after it arrived in the terminal. He and several passengers were reportedly injured, but the extent of injuries is unknown. Passengers believed the explosives were firecrackers, at first.
Here is Delta's statement, via NPR:
Upon approach to Detroit, a passenger caused a disturbance onboard Northwest Airlines Flight 253. The passenger was subdued immediately and the crew requested that law enforcement meet the flight upon arrival. The flight, operated by Northwest using an Airbus 330-300 aircraft with 278 passengers onboard, landed safely. The passenger was taken into custody and questioned by law enforcement authorities. Delta is cooperating fully with authorities and additional questions should be directed to law enforcement officials who are leading the investigation.The suspect is also rumored to be on a no-fly list.