Deadliest bridge collapses in last 20 years

A major rescue effort is underway in the US city of Baltimore after a container ship struck a key bridge, sending several vehicles plummeting into the Patapsco River.

At least 137 people, including nearly 50 children, were killed after a 150-year-old suspension bridge collapsed in Gujarat, days after reopening following renovations.

An elevated section of track on the Mexico City metro system collapsed in May bringing a passenger train crashing down, killing 26 people and injuring dozens. An investigation concluded that the accident was caused both by structural flaws and lack of maintenance. (Photo/Agencies)

The collapse of a bridge in the Italian city of Genoa killed 43 people. The Morandi bridge, part of a key highway connecting France and Italy, collapsed due to torrential rain in August, sending dozens of vehicles and their passengers tumbling into the abyss. (Photo/Agencies)

In March 2016, the collapse of a flyover onto a busy street in Kolkata killed at least 26 people.

Investigators say workers who were welding the bridge at the time noticed cracks appearing but that instead of warning people they tried to weld the cracks together.

In late 2011, two bridges collapsed within a week of each other -- one near the hill town of Darjeeling in the northeast, the other over a river in the northeastern state of Arunachal Pradesh. Over 60 people were killed in total. (Photo/Agencies)

At least 64 workers were killed in August 2007 when a river bridge in China's central Hunan province collapsed, as they were completing its construction. (Photo/Agencies)

In August 2006 in Pakistan, at least 40 people died as monsoon rains washed away a bridge in Mardan, 50 kilometres (30 miles) from Peshawar in the northwest of the country.