Residents of a southeast suburb are scratching their heads after experiencing a loud "boom" and feeling the earth shudder early on Sunday evening. Cornubia resident Shaun Pask said his West Coorang St house was rocked by the event which took place just before 6pm. Mr Pask said he felt as if a large object had hit the roof of his house. "My wife and I were inside when we experienced the house shuddering - it was so loud I could not image any handheld device could possibly create that amount of noise," he said. "It was not a small object hitting a small part of the roof - it was like something fell from the sky and it landed on our whole roof at the one time. "It was like a sonic boom hammered down on the entire roof and neighbours said they had the same experience." Nearby resident Glen Sheriff, who lives in 3km away in Wuduru Rd, backed up the claims and said his family also experienced the "boom". "It's got everyone in Cornubia a bit worried but if it was something electrical-related