Hardware failure is something that is expected to happen, but it will not be the reason that you lose your databases.

Just as replication is provided for storage, there is a similar safeguard for Azure SQL Databases.

If hardware failure occurs, there are three copies of your database, separated across three physical nodes. The three copies consist of one primary replica and two secondary replicas, and, to avoid any data loss, write operations are not committed in the primary replica until they have been committed to one of the secondary replicas. Therefore, whenever hardware failure occurs, it will fail over to the secondary replica.