HydrOlock....and it'* when the cylinder fills with water. That wouldn't have happened while the engine was running. Usually only when you try to start it. Water won't compress, so when the cylinder comes up, BOOM. Bad things happen.
If the intake failed while the car was at least idling, it couldn't have hydrolocked. It could have still seized the engine though.
Series 1 are prone to failure as well, just not as often or as badly. Both at the EGR port, and around the base where the seal is.
The risk of Hydrolock is the main reason I no longer run my water/alcohol injection.