BROOKLYN PARK (AP) -- Police have seized records from a Brooklyn Park home care agency as they investigate the deaths of two patients whose ventilator machines stopped working.

Investigators collected potential evidence from Plateau Healthcare following the deaths of 41-year-old Taurus Grantham last October and 49-year-old Douglas Palm in September 2016. Both men had Lou Gehrig's disease, or ALS.

A search warrant affidavit says in both cases Plateau nursing staff failed to respond when the ventilators stopped working. The police search also included the employment file of a nurse who was caring for Grantham just before he died.

Plateau's president, Faisale Boukari, says his company is cooperating with police in the investigation.