Contractors and Subcontractors: Chain of Responsibility for a Contractor's Mistake

My question involves a consumer law issue in the State of: MA

A contractor was conducting repairs in my condominium (the common area of the condominium). The contractor was hired by the HOA.

That contractor carelessly damaged a piece of equipment servicing my unit and thus caused damage to my property. The HOA management is trying to completely stay out of it.

So the question is, fundamentally - who is responsible? If I have to sue anybody who do I sue? In what order?

Thanks.

Contractors and Subcontractors: Chain of Responsibility for a Contractor's Mistake