ATLANTA — Officials at Atlanta's Hartsfield-Jackson International Airport say a small explosion and power outage was likely caused by a malfunctioning power supply unit.

Airport spokeswoman Reese McCranie says a unit that supplies power mostly to the air conditioning system at Concourse D malfunctioned Tuesday morning. Officials said the explosion didn't create a fire, but did cause some property damage.

McCranie says about 35 flights were delayed by an average of between 20 and 30 minutes, and officials plan to inspect the equipment Tuesday night to try determining what led to the explosion.

McCranie says an alternate power source is serving the concourse where the explosion happened.