WATCH: Nobody hurt in dramatic sink hole collapse on US football pitch

A huge '100 feet wide and up to 50 feet deep' sink hole has opened up on a football pitch in Illinois, US.

The sinkhole can be seen swallowing a light pole, benches and the artificial turf of the field at Alton's Gordon Moore Park.

Local reports have said that the collapse happened because of a nearby limestone mine.

Thankfully the sinkhole appeared when no one was on the field, so no one was hurt, and surrounding roads and areas were closed for safety.

What are sinkholes and how do they happen?

Sinkholes are quite rare and form when ground collapses, leaving a big hole.

It happens when soft rock underneath the surface loses strength, often because it's been dissolved by water.

Sinkholes can vary in size from big, enormous or small holes.

This HUGE sinkhole appeared in a field in Turkey last year

Areas on top of limestone or chalk are more at risk of a sinkhole happening as rainwater is able to dissolve soft rock like this.

This is why they are common in Florida in America, as the entire state is built on a limestone platform.

But generally, they are less common in places such as the UK.

Usually sinkholes are formed over a long time, but it can be difficult to guess where and when they might happen.

However some can be man-made and happen because of things such as a burst water pipe.

This sinkhole in China contains its own ecosystem - an ancient forest

Some sink holes have even been found to contain some surprises.

In 2022, scientists discovered a 630-feet-deep sinkhole which contained an ancient forest in southern China.