Is there any option to make the fourth block follow immediately after the first one without the “indent” at the top, which is obtained from the height of the first line?
There is an option to divide the container into 2 divas of 50% each and throw blocks into each, then they will be under each other. But is there an option without it in nature?

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"> <div style="background-color:#ff0;" class="container-fluid"> <div class="row"> <div style="background-color:#f00; height:20px;" class="col-1 col-sm-6">1</div> <div style="background-color:#0f0; height:30px;" class="col-1 col-sm-6">3</div> <div style="background-color:#00f; height:40px;" class="col-1 col-sm-6">4</div> <div style="background-color:#0ff; height:55px;" class="col-1 col-sm-6">2</div> </div> </div>