Fans roared in excitement and organizers sighed with relief as the Tomorrowland music festival kicked off Friday — two days after a massive fire engulfed the main stage and threw one of Europe's biggest summer concert events into doubt.

The cause of the fire remains unknown. No injuries were reported in the incident, according to festival organizers.

Video showed thick plumes of black smoke rising from the famed festival grounds in Boom, Belgium on Wednesday. Fireworks could also be seen and heard going off in the distance.