What safety measure should be taken before beginning to dig?

Identifying and marking all utility lines before starting to dig is crucial for ensuring safety and preventing accidents. Utility lines, including gas, electricity, water, and telecommunications, can be running underground in the area where digging will take place. If these lines are struck during excavation, it can lead to severe injuries, service interruptions, and costly repairs.

Marking utility lines allows workers to be aware of their presence and take necessary precautions to avoid damaging them. This step is a foundational safety protocol in construction and excavation practices, aiming to minimize risk and protect both workers and the public.

The other options do not adequately address the immediate safety requirements associated with digging. Starting to dig immediately disregards the potential dangers, while consulting with an engineer may provide useful insights but does not directly mitigate immediate risks related to utility lines. Inviting public attendance could lead to dangerous situations by exposing untrained individuals to excavation sites without addressing the underlying safety concerns.