A modern jetliner crashes with 228 people on board. An oil refinery erupts in Utah, sending shockwaves through town and damaging over 100 homes. Manhole covers explode around the country, killing people and destroying property.

Throughout history the same builders and engineers that paved man's path out of the caves also caused some of mankind's worst disasters. Often a huge calamity is traced back to a tiny cause, insignificant in itself, but triggering a domino effect.

A single train crossing was the site of not one, but two disastrous auto collisions in a single year. How could this happen?

Nine dams in Colorado are taken out by a storm, flooding entire towns and leaving thousands stranded. Toxic vapours throughout a small NJ community after a train is derailed.

An explosion in a San Bruno, California destroys homes and kills residents. An experienced captain and crew sail their ship into the path of Hurricane Sandy, leaving many asking why. Was it an engineering failure or human error?

Why did Asiana flight 214, packed with passengers, suddenly crash land and cartwheel across San Francisco International Airport's runway? Three families of the dead want answers.

A mudslide that swallows an entire neighbourhood and leaves scientists baffled is investigated. Plus, could engineering be to blame for the deaths of more than 200,000 people in Haiti?

There's a gaping sinkhole at the National Corvette Museum - can a team of engineers fix it? And, what caused the collapse of Minneapolis Metrodome's iconic roof?