Typhoon Haiyan which struck central Philippines on Friday unleashed winds of over 300 kilometers per hour and "tsunami like" waves, causing devastation that caught emergency planners in the country off-guard.
One of the strongest storms ever recorded, Haiyan killed an estimated 10,000 people, Reuters reported, citing Leyte province police chief superintendent Elmer Soria.
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Nearly 620,000 people were displaced and 9.5 million affected across nine regions, the U.N.'s Office for the Coordination of Humanitarian Affairs (OCHA) said in a statement. Hurricane Katrina, which struck the U.S. Gulf Coast and Florida in 2005, killed over 1,800.
Though the Southeast Asian nation of close to 97 million is beset by powerful tropical storms and occasionally violent earthquakes, officials said they underestimated just how powerful Haiyan - or typhoon Yolanda as it's called locally – could be.
"We're used to Level Four typhoons but this was different because of the storm surge," Lt. Col. Ramon Zagala told CNBC on Monday. "It was like a tsunami."
Tacloban, the provincial capital of the central Leyte province that bore the brunt of the storm, lies in a cove where the seawater narrows, Reuters reported. That makes it susceptible to storm surges, a rising of the sea level due to low pressure, high winds, and high waves.
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The Federal government in Manila "knew it was going to be bad but didn't expect this," Alex Magno, a political columnist for The Philippine Star told CNBC.
Philippines President Benigno Aquino was forced to walk out of a meeting with local government officials in Tacloban City after furious survivors interrupted the gathering to berate him for the authorities' slow response to the disaster, the U.K.'s Daily Telegraph reported on Sunday.
The authorities activated emergency plans in preparation for Haiyan, issuing public early warning notices, evacuating residents and pre-packing essential supplies ahead of the impending typhoon, Mathias Eick, the European Commission's Humanitarian Aid (ECHO) Regional Information Officer for East and Southeast Asia, Pacific Region told CNBC.
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Again, officials didn't account for the system's sheer destructive power, Eick said. "No one expected a storm surge of 5 to 10 meters," he said.
— By CNBC's Sri Jegarajah. Follow him on Twitter: @cnbcSri