A Dallas police officer died on Wednesday, one day after he, another officer and a store security guard were shot at a Home Depot.

The officer, Rogelio Santander, and a fellow officer, Crystal Almeida, were at the store responding to a request for assistance with an arrest. Officer Santander died from his injuries at 8:11 a.m., according to the Dallas Police Department.

“Our hearts are aching because of this Dallas police officer who lost his life in the line of duty,” Gov. Greg Abbott of Texas said on Twitter. “We thank him for paying the ultimate sacrifice protecting his community and we keep his family in our prayers.”

Officer Almeida and Scott Painter, the Home Depot security guard, both remain critically injured, Chief U. Renee Hall of the Dallas Police Department said at a news conference on Wednesday.