A 7.7-magnitude earthquake centered in war-ravaged Myanmar reverberated across Southeast Asia on Friday, killing at least three people each in Myanmar and neighboring Thailand and leaving scores of others trapped under a collapsed high-rise in the Thai capital. The number of casualties in bot h Myanmar and Thailand are expected to rise. The earthquake occurred around 1:30 p.m. local time (2:30 a.m. ET) at a depth of 6 miles near Mandalay, the second-largest city in Myanmar, according to the U.S. Geological Survey. It was followed minutes later by a 6.4-magnitude aftershock. The Thai capital of Bangkok, where many of its 17 million people live in high-rise apartments, was declared a disaster zone after the quake sent buildings swaying and forced thousands of people to evacuate their homes and workplaces. At least three people were killed when a 33-story building under construction collapsed near the popular Chatuchak market. More than 80 others remained trapped in the rubble, Defense Minister Phumtham Wechayachai said. Footage from NBC News crew on the ground at the Bangkok building collapse showed local crews among the rubble, including some with rescue dogs, as they assessed the damage on site. In Myanmar, initial reports on the impact of the earthquake indicate significant damage in the centre of the country, an official from the United Nations Office on Humanitarian Affairs. Videos posted online and verified by NBC News showed construction workers running from the crane-topped building as it collapsed in a plume of smoke. Other videos showed damage to a motorway, passengers evacuating Bangkok’s Skytrain and water sloshing out of rooftop swimming pools. Bangkok earthquake right now #bangkok #earthquake #bkknews #bkk #แผ่นดินไหว pic.twitter.com/iKGUnc7Exd— Sebastian Wolff (@sebastianwolffX) March 28, 2025 “All of a sudden the whole building began to move. Immediately there was screaming and a lot of panic,” Fraser Morton, a tourist from Scotland who was in a Bangkok mall, told the Associated Press. Those who evacuated sought out shade as officials urged them to stay outdoors in anticipation of more aftershocks, which can come hours after the initial event. The Thai Stock Exchange closed after the quake, local media reported, while authorities said in a Facebook post that Bangkok’s main airport was operating normally. The military government in Myanmar, where a civil war has been raging for four years, also declared a state of emergency in multiple regions, including Mandalay and the capital, Naypyitaw. “The state will make inquiries on the situation quickly and conduct rescue operations along with providing humanitarian aid,” it said in a statement, according to Reuters. At least three people were killed after a mosque partially collapsed, Reuters reported. In addition to the collapsed 90-year-old bridge in the Sagaing region just southwest of Mandalay, sections of the highway connecting Mandalay with Myanmar’s largest city, Yangon, were damaged, the AP reported. The quake also damaged religious shrines and some homes in Naypyitaw. The overall extent of the damage was not immediately clear, but Myanmar’s government said blood was in high demand in the hardest-hit areas, and videos from the country showed multiple collapsed houses and buckled and cracked roads.  Getting humanitarian relief into the worst-hit areas of Myanmar “might not be politically easy,” said Ilan Kelman, a professor of disasters and health at the Institute for Risk and Disaster Reduction at University College London. He noted that in 2008, when Cyclone Nargis killed more than 130,000 people in Myanmar, the government took days to accept significant aid and then hindered its delivery. The military has tightly regulated entry into the country since seizing power in a coup in 2021. Tremors were also felt in the southwestern Chinese province of Yunnan, which borders Myanmar. In the border town of Ruili, residents ran away from a high-rise residential building as it shook violently, according to a video posted on the Chinese social media platform Weibo and geolocated by NBC News. The earthquake on Friday was probably the biggest on the Myanmar mainland in three-quarters of a century, said Bill McGuire, a professor of geophysical and climate hazards at University College London.  “A combination of size and very shallow depth will maximize the chances of damage,” he said. “It is highly likely that build quality will generally not be high enough to survive this level of shaking, and casualty numbers will almost certainly climb significantly as more becomes known of the scale of the disaster.” Nat Sumon and Kyle Eppler reported from Bangkok, Matthew Mulligan from London and Mithil Aggarwal from Hong Kong. This story first appeared on NBCNews.com. More from NBC News: Trump takes aim at foreign-born college students, with 300 visas revoked Hegseth, facing scandal at home, reaffirms U.S. support for the Philippines against China Rain and cooler weather help South Korean fire crews battle devastating wildfires ...read more read less