Engineers at a newly-discovered cave site on Cambria Drive in Williamson County found a fourth chamber in the cave Monday afternoon, making it 200 feet long.

Structural engineers with Dunaway Associates were at the cave site Monday. The county said Cambria Drive will remain closed for several weeks.

The cavern was discovered when a 20-foot hole opened up Thursday morning revealing the cave.

According to a press release from the Williamson County Public Information Office, county officials and environmental consultants found the cave in Cambria Drive starts approximately in the middle of the roadway 20 feet west of the curb, and heads east by approximately 200 feet.

The height of the cave was found to have varying heights of approximately 22 feet near the entrance with an average of 10 to 15 feet throughout.

The county said there are 6 to 8 feet of limestone and sediment between the homes and the cave ceiling.

Municipal Utility District officials said the hole was caused by the roof of a cave that collapsed on top of a water line.

Michelle Mitchell lives in one of the three homes above the cave.

"It's not how you expect to start your day literally with, 'Hey, a cave opened up,'" she said.

At 3 a.m., some homeowners called the Municipal Utility District to complain about low water pressure, while others said they had no water at all, which was what prompted the discovery of the cave. By 2:50 p.m. Thursday, the Brushy Creek MUD reported that all 10 homes remained without water but, the service was restored at around 4 p.m.

Officials said the collapsed cave is one of the biggest they've ever seen.

PHOTOS: Cave discovered under homes in Williamson County

Cambrian Environmental was also at the scene to assess the damage. Williamson County is working with the Texas Commission on Environmental Quality to determine the best solution to repair the neighborhood where the cave was revealed.

It is still unknown exactly what caused the opening, however, officials said the initial examination shows that the limestone bed that forms the cave's ceiling is scored and thinner where the utility lines were installed, and the cave ceiling seems to be more stable outside of that area.

Officials are encouraging the public to stay safe by staying behind the safety fencing.