Yes, if a fully formed soda can is placed underneath the ocean at sufficient depths, it will be crushed. The crushing of objects underwater is primarily due to the increasing water pressure with depth. As you descend deeper into the ocean, the pressure exerted by the weight of the water above increases. This pressure can be immense, especially at great depths.
The exact depth at which a soda can would be crushed depends on factors such as the thickness and strength of the can's material, but in general, at depths beyond a few hundred feet (around 100 meters), the water pressure becomes substantial enough to deform or collapse thin-walled objects like soda cans.
The typical soda can is not designed to withstand the extreme pressure found at the depths of the ocean. As a result, the can would likely buckle, crumple, or collapse under the increasing pressure until it is completely flattened.