Hundreds of residences and several hotels in the Torrey Pines, Del Mar and Carmel Valley areas were under a boil-water order Monday following a major water main break, authorities said.
The break in a 36-inch water main in a canyon in northwestern San Diego was discovered overnight, according to San Diego Water Department spokesman Arian Collins. Service was restored by 4:30 a.m., he said.
Because bacteria and other organisms could have contaminated the water while the main was broken, a boil-water order was issued. Collins said the order could remain in force for up to 72 hours or until follow-up testing deems the water safe.
Under the order, all tap water used for drinking or food preparation should be boiled for one minute and then cooled before use.
The cause of the break was under investigation.