Odaily Planet Daily News According to mempool data, miners mined an empty block at Bitcoin height 868664 (i.e., the block only contains one transaction, the block reward Coinbase), with only a 42-second time interval from the previous block height. Miners pack empty blocks out of economic considerations; doing so is the wisest choice for miners. In order to make the most of this period for mining and avoid conflicts with transactions packed in the parent block, miners cannot fill the block with transactions, meaning that miners can only attempt to mine empty blocks.