The early February explosion that torched Hong Kong Lounge II took out several other buildings too, and tenants accuse Verizon and its subcontractors of negligence.

It’s pretty miraculous that no one was injured in the Feb. 6 gas line explosion that shot 40-foot flames into the air at an Inner Richmond corner. But a number of state and federal authorities have since determined that the contractor that ruptured the Geary Street gas line was unlicensed, and residents who lived at the five destroyed buildings are alleging further recklessness. Two of them have sued Verizon and a number of other contractors, according to Bay City News, accusing the companies of “reckless and willful violation of California law.”

You probably haven’t heard of contractors like Mastec Renewables Construction, Kilford Engineering, and Advanced Fiber Works, unless you happen to work in the subsurface installation or construction industries. But all three are co-defendants, along with Verizon, in a suit that accuses them of skirting state laws by using machines instead of the required handheld tools when they ruptured the gas pipeline.

“Ultimately you’ve got contractors doing work near high-pressure distribution gas lines in a high-density area like San Francisco,” the plaintiffs’ attorney Ara Jabagchourian told Bay City News. “You would think that every precaution would be taken following state law, including not using heavy machinery near gas lines.”

Early SFFD estimates concluded that around 100 people were displaced by the fire, according to KGO, and the lawsuit details the plaintiffs’ anguish over losing their homes and possessions. This San Francisco Chronicle slideshow gives you an idea of the devastating extent of the damage.

All of the construction firms were essentially third-party contractors working for Verizon, installing underground fiber optic lines. KTVU reports that Cal-OSHA has opened their own investigation into the subcontracting firms’ handling of the incident. Mastec has three prior violations, albeit far smaller ones, whereas Kilford Engineering and Advanced Fiber Works do not have any history of OSHA violations.

Related: Site of gas line explosion in San Francisco was properly marked, PG&E says [Chronicle]