One of the oldest courthouses in Tennessee caught fire on Tuesday night. Investigators said the fire began at around 6:30 p.m. on April 23.

By about 10:30 p.m., firefighters were able to enter the building after hours of fighting the flames; however, hot spots remained.

Around 10:20 p.m., the roof of the courthouse appeared to partially collapse. The tower section remained standing, but the back half of the roof appeared to cave in,

Fire crews worked throughout the night, taking shifts battling the blaze. Some even slept on the lawn when the fire was finally out.

Loudon police said the metal roof on the courthouse made it more difficult to extinguish the fire, because it impeded efforts to get water onto the flames. Several side streets in the area around the courthouse will remain closed Wednesday, but Highway 11 is now reopened.

Loudon County Mayor Buddy Bradshaw said the courthouse could be a total loss, and roads in the area would likely remain closed through Wednesday, April 24. The mayor said early reports indicated the fire may have started from a light switch in one of the courthouse rooms; however, further investigation was underway to confirm an exact cause.