Tragic moment underwater blue hole was unsealed after 40 years ending in huge disaster

In New Mexico there is a blue hole which was sealed up for 40 years, only for disaster to strike when the bottom of the hole became unsealed by a group of divers.

The Santa Rosa Blue Hole is a popular tourist destination in the US, and a spot plenty of divers have enjoyed.

However, at the bottom of this blue hole is a system of caves and passages, with a series of incredibly tight spaces that made it difficult to navigate with diving equipment.

Lots of divers have enjoyed the Santa Rosa Blue Hole. (Getty Stock Photo)

The caves at the bottom of the Santa Rosa Blue Hole were sealed up in 1976 to stop inexperienced divers from venturing inside after two divers-in-training died after getting separated from their group.

A metal grate was placed over the cave entrance at the bottom of the blue hole, while rocks and debris were dumped inside to help seal it up.

However, 37 years later the ADM Exploration foundation gained permission to explore the caves again, but found their way blocked by the debris.

Footage from one of the earlier dives showed just how difficult it would be to move and see. (YouTube/Mike Young)

Three years later in 2016, after the debris had been fully cleared, another expedition went down to fully explore the caves at the bottom of the blue hole.

Experienced divers Shane Thompson and Mike Young went down into the caves, though according to The Guardian, only Young was supposed to go in as far as possible while Thompson remained outside for safety purposes.

Instead, both men went into the caves and Thompson died down there, resulting in the entrance being blocked up again.

According to police 'something went horribly wrong, and he [Thompson] started to panic', and his following Young into the final caves was not part of the plan.

Footage taken by Young of a previous dive in the Santa Rosa Blue Hole where debris was dug away from the entrance. (YouTube/Mike Young)

With Young kicking up a lot of silt as he swam through the caves and not knowing his diving partner had followed him, Thompson's visibility was blocked.

As the divers attempted to make their way out of the caves their guide line snapped and they became separated.

Young slowly felt his way through an alternative route until he was able to rediscover the line, and followed it back into the caves to help Thompson.

However, the guide line went limp and Young knew that his diving partner had died.

While he was able to find Thompson's body, Young wasn't able to get it out of the caves by himself and had to surface.

Thompson's body was recovered from the caves the following day and the caves at the bottom of the Santa Rosa Blue Hole were sealed away once more.