The Texas parents of a child who died last year at Nebraska Medical Center after an overdose of blood thinner are suing the hospital.

Greg and Kenya Duque of Dallas filed the wrongful death lawsuit this week in Douglas County District Court. While the lawsuit does not specify the amount in damages sought, it does ask the court to declare unconstitutional a Nebraska law capping awards in hospital liability cases at $1.75 million.

Hospital officials acknowledged last year that a Heparin overdose contributed to the March 2010 death of 23-month-old Almariah Duque. The toddler was being treated for an infection following a multiple organ transplant she received in December.

The Duque's lawsuit says Almariah was given 10 times the amount of Heparin she was supposed to get, causing her death.