Guests were allowed to go back into the Gaylord Opryland Resort & Convention Center at around 3 a.m. this morning after an explosion in a mechanical room forced their evacuation Tuesday night. There were about 5,000 guests that had to be evacuated after the explosion on the first floor in the Delta area of the hotel at around 8:15 p.m. Tuesday. The explosion occurred in a mechanical room and officials believe it was caused by a gas leak according to the preliminary investigation, Metro Police Capt. Ken Walburn said.