Some of them sent messages via mobile phone asking help. It’s supposed that some under-age workers were employed too. The collapse happened just over a week after a magnitude-7.5 earthquake hit Pakistan, killing 273 people and damaging nearly 75,000 homes. The cause of the building collapse is not yet determined. A large rescue operation is underway, which includes a team of army engineers and urban search-and-rescue personnel. The factory was at the end of a narrow lane making it difficult for excavators to reach the site. Dozens of the workers’ families rushed to the scene of the incident. Building safety levels are often below standard in Pakistan. Last year, a mosque collapsed in the same city, killing at least 24 people.