Once making it to the outside for first time, where you have to run to the bunker and go down the ladder. After doing that and the two soldiers rappel down, once you kill them and jump down to the vent it crashed. The popup said the following:
Engine Error
Can’t load lump 53, allocation of 17019609 bytes failed!!!
I hope this helps. BTW AWESOME job on the game guys!!
After reloading BMS, it goes through where I last crashed without a problem, guess it self corrected.
The wait for this game was worth it! Thanks again!
It didn’t self correct, it just didn’t trigger.
That bug is most likely due to rushing of some sort.
Triggering alot of stuff, overloading effects, etc.
Oh ok, well I haven’t had anymore crashes since then 
Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.