Flooring Tile - Removing tiles

I have some old ceramic tiles in a house I just bought. There's a crack running down them the whole length of the room, and through the middle of the tiles.
I want to remove all the tiles and put a new design in. What's the best way to remove all tile, and what should I do with the crack under them if that's what caused them to crack in the first place?

Removing tiles requires goggles, hammer, and chisel, and perhaps pry bar. There are pneumatic chisels at the tool rentals. If the floor has cracked all along through the middle, then there may be structural issues. If on a concrete slab, the slab has likely cracked. If on a wood subfloor, perhaps foundation or pier settlement, beam, or joist problems may exist. These issues must be addressed in order to determine the cause of the cracked tiles and the best approach to address the issues.

When installing tile on wood subfloor, concrete underlayment board is recommended. Any movement in subfloor tends to result in cracked grout and possibly cracked tiles.

Keep us posted on your investigation and keep us up to date with your project.

It sound as if your crack is in a straight line--- you are lucky
Isolate the damaged tiles from the rest of the floor by first removing the grout between the damaged tiles and the rest of the floor . There are various tools available for doing this.Circular saw with concrete cutting blade is fast and VERY dusty.
Dremmel tool has a grout cutter available- so does roto-zip.
Hand removing saws are very slow and a lot of hard work.

After tiles are removed determine what caused crack. Re-post with more information.