A towering arch bridge over a bay in eastern Taiwan collapsed on Tuesday, sending an oil tanker lorry falling onto boats in the water below.
The search for potential victims involved an air force helicopter and more than 60 army and naval personnel, including divers.
Six people are believed trapped on one of the boats, the National Fire Agency said in a statement.
Interior Minister Hsu Kuo-Yung told reporters about five people were feared to have been on the bridge when it collapsed.
Ten people were sent to hospitals, six of them with serious injuries. Of the 10 people hospitalized, six are Filipinos and three are Indonesians, the agency said in a statement. People from both countries regularly staff Taiwanese-registered boats.
Other reports said at least 14 people were injured.
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Fishing vessels were helping to search for the missing, Hsu told Formosa TV.
The bridge collapsed about 9.30 am in Nanfangao, a tiny but often-crowded Pacific coast fishing village.
The weather at the time of the collapse was sunny, hours after a typhoon swept across parts of the island.
Disaster relief officials would not say if the storm had weakened the bridge or give other details on the potential cause. Government-run Central News Agency said a bridge pier may have collapsed.
Taiwan President Tsai Ing-wen said she hoped all government departments would do everything possible to save people and “keep the number of deaths and injuries as low as possible,” CNA reported.
National Fire Agency spokesperson Su Hong-wei said the tanker’s fall smashed three boats.
Typhoon Mitag had brought high winds and heavy rain to northern Taiwan on Monday night before moving northeast. Flights and ferry services had been canceled on Monday.
The 140-meter-long Nanfangao Bridge is a tourist attraction in Yilan. It was opened in 1998 and was built to replace a lower bridge that prevented large fishing vessels from passing underneath.
According to the company that designed the 18-meter-high high bridge, MAA Consultants, it’s the only single-span arch bridge in Taiwan supported by cables and the second single arch-cable steel bridge in the world.
Video footage on Twitter showed a large lorry almost getting across the bridge and then tumbling backward as the bridge collapsed into the water.
The lorry then burst into flames, sending a thick plume of black smoke into the air.