A grounds maintenance worker who was seriously injured in an accident on campus last week is now in stable condition, hospital officials said Sunday night.

Anna Lizasuain was pinned against a wall Wednesday while using a hand-operated lawn aerator. Despite her improvement from critical to stable condition, she remains in the Surgical Intensive Care Unit at Yale-New Haven Hospital and is not expected to recover fully in the near future. The accident is one of the worst work-related incidents at Yale in more than 30 years, University and union officials said, and has prompted a safety review of the aerators.

Though Lizasuain remains in the ICU, her health has slightly improved in the last few days, Local 35 President Bob Proto said. She was scheduled to have CAT and MRI scans done last Friday to evaluate the extent of the head and spinal trauma, Proto said.

Lizasuain was injured while using a lawn aerator — which makes holes in the ground to reduce soil compaction — at 80 Sachem Street, a building used by the School of Management near Science Hill. She was operating the machine when she accidentally backed into a wall and was pinned against it by the aerator, said Director of Facilities Operations Eric Uscinski, who did not witness the accident. An employee in the office building found Lizasuain, he said, who was then brought to Yale-New Haven Hospital.

Yale’s lawn aerators are hand-operated and range from three to seven feet in length, Grounds Maintenance Supervisor Walter Debboli said. Uscinski said he could not recall this type of problem happening with one of Yale’s aerators before. But the machines have been taken out of service pending a review of the equipment by Yale’s Office of Environmental Health and Safety, he said. The safety review has not yet been completed, but results should be available in within a few weeks, Uscinski said.

Proto said he had not heard of repeated problems with the lawn aerators, though he is not very familiar with that particular piece of equipment.

“None of my stewards reacted with an ‘I told you so’ attitude,” he said, referring to Local 35 union officials.

Proto and Uscinski said Lizasuain’s injury is the most serious work-related accident they can recall in their three decades at Yale, though Proto said employees have passed away on the job before due to medical conditions. The accident was significant enough that the federal Occupational Safety and Health Administration responded to the scene, Uscinkski said. He said he did not know who had called OSHA.

Proto said both the union and University have stepped up to help aid Lizasuain’s family in any way possible. He said he heard directly from Vice President for Finance and Administration Shauna King with an offer to help. Cielo Lizasuain, Anna’s husband, is also a Yale employee, and arrangements may be made so he can have additional time off, Proto said. The University’s cooperation has been “tremendous,” Proto said.

Anna Lizasuain arrived at Yale in 1988, according to her husband. She began her career at Yale with dining services, then moved to custodial services and finally to grounds about four years ago. If you find yourself in a situation similar to Anna Lizasuain, it is critical that you work with a work site accident attorney to negotiate a more favorable settlement for you.