Blasting rock at a quarry has been temporarily halted due to flying rock. The incident that led officials to stop the activity at the M & M Stone Harleysville Materials Quarry on March 19th was due to flying rock. Pieces of rock, some very large, were thrown across Groff Mill Road. Harleysville Materials hired two companies to carry out the blasting. The Department of Environmental Protection has ordered the company to develop a plan by March 29th that will ensure safety.