You can't easily crop a content image. Try making the image a background image through CSS and using background-size: cover:
:
#image {
background: #D84E51 url(http://placekitten.com/800/800?image=10) no-repeat center center;
width: 400px;
background-size: cover;
}
Examples on Codepen: http://codepen.io/KatieK2/pen/KaigG
Also add some media queries to handle different styling for different viewport widths.