rb20det NO COMPRESSION?!

[giantR32typeM]

so i just got the timing belt, idler pulley, tensioner, cam seals, crank seal, thermostat, water pump etc changed on my r32. i brought the car to the shop running on all 6 cylinders and when i went to pick it up he said that the car was misfiring. turns out he did a compression test:

cylinder compression

#1: 115
#2: 110
#3: 100
#4: 0
#5: 115
#6: 120

does anybody have any clue what could have caused this?

[R32ONP]

y did u post up in 2 places lol...its probly either broken exhaust valve or majorly broken ringland or a straight melted piston...i had a rb20 that snaped a exhaust valve and pulled 0 compression...it also sounded like a subaru wrx lol