Do I need workers compensation Santa Monica

[Scott Malkin]

I have a 10 unit building in Santa Monica. No employees apart from a gardener who is self-employed. Do I need workers comp insurance? Already have apt owners insurance through State Farm as well as a commercial liability umbrella policy? Will I be covered if a plumber or handyman without their own insurance policy is injured at my building?  Or better yet, what if I reimburse one of my entitled rent control tenants to paint their apt and they 'slip and fall'....

Thanks !