GAZIANTEP, Turkey — In the southern Turkish city of Gaziantep, the epicenter of Monday’s earthquake, some people fled their homes in the cold and rain and took shelter in their cars when the earth began trembling before dawn.

As they waited for it to end, and for the sun to rise, bad news filled their phones before they could see for themselves the damage that had been wrought by the 7.8 magnitude quake that has left more than 1,000 people dead, a toll that was almost certain to rise.

One man burst into tears after learning that his brother was stuck under the rubble of a fallen building. Others received news that their homes or those of their relatives were heavily damaged. Many wounded were rushed to local hospitals. The city’s ancient castle was heavily damaged.

A security camera in a store in Gaziantep, also known as Antep, captured the moment when the main earthquake struck. Footage showed shelves rattling for at least one minute and 30 seconds, with furniture and appliances falling and shattering on the floor.

Davut Gul, governor of Gaziantep, tweeted that the earthquake was “felt severely” in Gaziantep, a city of more than two million inhabitants. He urged people to wait outside for the shaking to end, and to leave the main roads empty.

Millions of Syrian refugees in Turkey live outside the city of Gaziantep. Turkey hosts the largest number of Syrian refugees in the world, 3.6 million, according to the United Nations High Commissioner for Refugees, which runs one of its largest operations from Gaziantep.

Similar scenes were playing out in other cities and towns across Turkey and Syria after the earthquake, one of the strongest ever recorded in Turkey. Videos on social media verified by The New York Times showed collapsed buildings, crushed cars and emergency services mounting rescue and recovery operations.