The two classics in 2007 were shooting in the same area around the same time, which created issues when a pyrotechnic test for There Will be Blood created a huge smoke cloud that got into a shot for No Country For Old Men. The Coen's had to wait for it to dissipate before filming.

http://bit.ly/2ROFLsf via /r/movies http://bit.ly/2Hl3MmE