Oh no!!! 3 of the 4 fall broccoli plants have been killed! (they were still skinny)

Noticed about a week ago that one of the four piracicabas that I direct-seeded a while ago had floundered, didn't think too much as 3 were still left.  Well!  Today I noticed 2 more have died!!  The stem was sliced clean through, about 1.5 inches above soil level.  Cutworm maybe!?  (As they've been always under floating row cover.)

Bummer.  One is still there... for now.  I won't bother doing anything about this, will just see if this one makes it.  But in future years, I should avoid direct seeding broccoli in favour of waiting until plants are good and sturdy before putting in the ground.