Massive Engineering Mistakes

In Canada, a tragedy strikes a busy shopping centre. In Missouri, a massive dam collapses within minutes. What caused these shocking catastrophes?

Saturday, 18 July 5 airings
06:00
Quest
S3 E1
07:00
Quest
S3 E2
21:00
Discovery History
S3 E4
22:00
Discovery History
S3 E5
23:00
Discovery History
S3 E6
Sunday, 19 July 3 airings
09:00
Discovery History
S3 E4
10:00
Discovery History
S3 E5
11:00
Discovery History
S3 E6