JAKARTA: Herman Wiharta began that Sunday morning like many 11-year-olds would on a weekend: watching cartoon shows on TV.

But at around 8 a.m., he felt the powerful tremors from a 9.1-magnitude earthquake that struck off the coast of Indonesia’s Sumatra island, which then triggered the tsunami that inundated the coastline of more than a dozen countries and killed some 230,000 people.

Wiharta, now 31, recalled his brother calling out to him to leave their house in Banda Aceh minutes after the quake and how they had attempted to run to safety. He remembered hearing people scream about the rising sea water before he himself was swept away by a giant wave.

“I lost consciousness when the wave hit me and I woke up on a roof, confused. Thankfully, my brother and sister were also on that roof,” he told Arab News.

“We were able to see just how black the water was from that spot, how strong the currents were. The water was about 4 to 5 meters high; cars and motorbikes were floating, and I could see bodies being swept away by the currents, too. It was terrifying.”

The tsunami on Dec. 26, 2004 quickly escalated into a global disaster, with some 1.7 million displaced.

The brunt of the tsunami was felt in Indonesia, where almost 170,000 people perished. The country’s westernmost province of Aceh was the hardest-hit of all, while Sri Lanka, India and Thailand were among the worst-affected countries.

“It was impossible to sleep that night. We could still hear people screaming for help and the dogs were howling. Everything was just so eerie. The disasters happened so quickly, but they were deeply traumatizing,” Wiharta said.

“It was even worse the day after. We could see bloated human and animal corpses, and the smell was just terrible. I can still picture that scene in my mind to this day.”

Across Asia on Thursday, people attended ceremonies and memorials held to mark 20 years since the deadliest tsunami in recorded history.

Coastal communities were united in grief as they also commemorated how far they had come after two decades of rebuilding and regrouping.

In Sri Lanka, where more than 35,000 people were killed, survivors and relatives gathered in the coastal village of Peraliya to remember the 1,000 victims who died when waves derailed a passenger train.

In Thailand, where half of the death toll of 5,000 were foreign tourists, commemorations were held in Ban Nam Khem, the country’s worst-hit village. People laid flowers and wreaths at a wall curved in the shape of a tsunami, which also bears plaques with the names of the victims.

In India, where around 20,000 people perished, women led the rituals held at Pattinapakkam beach in Chennai, where they lit candles and offered flowers for the victims.

In Banda Aceh city, an official ceremony held at the Baiturrahman Grand Mosque began with a three-minute-long siren at the exact time the major earthquake caused giant waves. People also gathered for prayers at the city’s mass graves — Ulee Lheue and Siron — where thousands of unidentified and unclaimed tsunami victims are buried.

In the years since, infrastructure across Aceh has been rebuilt and is now stronger to withstand major disasters. Early warning systems have also been set up in areas closer to shores, to warn residents of a potential tsunami.

Indonesia’s early tsunami warning system was launched only in 2008 in the aftermath of the disasters, said Daryono, the head of the earthquake and tsunami center at Indonesia’s meteorology, climatology and geophysical agency.

“Before the 2004 Aceh earthquake and tsunami … there were too many people who did not understand the threat, or the danger and risks of a tsunami,” Daryono told Arab News.

“But what happened in 2004 became a starting point to raise awareness on earthquake and tsunami mitigation and also to develop high-tech monitoring for earthquakes and early tsunami warning systems.”

Yet Aceh resident Wiharta was concerned with the direction of development in the province, particularly on the beaches of Aceh Besar district where many new cafes have been popping up in recent years.

“It’s important not to cut down the trees for the sake of building these cafes. It’s better to plant more trees, especially mangroves, so that they can help defend against potential tsunamis,” he said.

“I think the early warning systems also need to be fixed or reset to make sure that they are properly working for early evacuations, since many are either broken or stolen.”