A Springfield engineering firm has been sued for negligence after homes in the Moon Mountain development in eastern Eugene were damaged or destroyed because of ground instability.

“The ground destabilization resulted in significant property damage including destruction of one of the homes, loss of use of all three of the homes, and need for emergency stabilization and mitigation work on all three properties,” states the lawsuit, filed Tuesday, Dec. 16, in Lane County Circuit Court.

The lawsuit says that in February 2025, the homeowners at the time — Brendan Driscoll and Mandy Tang; Tristan McDonald and Sarah Anderson; and Keith Kulyk — reported problems to the developer, MonteVista Homes.

In March, the residents were forced to leave their homes, according to the lawsuit, which alleges negligence by Branch Engineering Inc. and engineer Ronald Derrick.

The homes were built and then sold between December 2022 and April 2024, and the lawsuit contends they were built “[b]ased on confirmation” from the engineering firm and Derrick that the three lots “were stable, safe, and sufficient for vertical construction.”

The lawsuit alleges that before the involvement of MonteVista Homes with the housing development, the Springfield engineering firm conducted technical evaluations for a previous owner. The lawsuit contends the engineering firm failed to disclose to MonteVista Homes “the issues it knew were present related to the slope stability and structural fill.”

The developer, MonteVista Homes, “reached resolution of the claims asserted by the former homeowners,” the lawsuit states.

The lawsuit claims financial losses in excess of $3 million, with the rights and interests of the developer and the homeowners now assigned to a limited liability company, Gritstone LLC, which is the plaintiff in the lawsuit.