D.C. Code § 34-2709
Compliance with the notice requirements of § 34-2704 shall not be required for an emergency excavation or demolition involving an imminent danger to life, health, or property; provided, that reasonable precautions have been taken to protect underground facilities. The appropriate utility operators shall, in any event, be notified directly and as soon as possible. The appropriate utility operator shall respond by marking the approximate horizontal location of the underground facility within 2 hours of notification of the emergency excavation or demolition, where practicable. An imminent danger to life, health, or property exists whenever there is a substantial likelihood that loss of life, health, or property will result before the procedures under § 34-2704 can be fully complied with.
D.C. Code § 34-2709