Why did the Lapindo Mudflow happen?

Class : Mipa 7'18

Member of group : 

1. Dian Nita Dwi  A (11)

2. Friska Triana Dewi (15)

3. Hidayatullah Arya W (17)

4. Nanda Aurelia (19) 

5. Umi Fauziyyah Firdausi (31)

https://youtu.be/P_b2pmwRmy8