Microsoft wasn't the only cloud company clobbered by the Dublin lightning strike in August. Amazon, too, was taken down during the dramatic lightning storm. According to Amazon, the Dublin outage took down its Elastic Compute Cloud (EC2) and Relational Database Service (RDS) for several days. Investigators found that a power failure caused the cloud outage, and that outage was sparked by a transformer exploding and catching fire. Lightning was thought to have caused the transformer explosion, but not confirmed 100 percent. Amazon said that backup generators failed to switch on once power went out and Amazon had to bring the generators back online manually to re-establish connectivity, which took several hours.