NEW YORK (CBSNewYork) — The NYPD is offering a $2,500 reward for information on suspects in connection with a deadly home invasion in Brooklyn.

Police say four thieves tied up 91-year-old Waldiman Thompson and his 100-year-old wife, Ethlin in their home in Bed-Stuy last week.

The couple owns the building and collects rent from tenants. Sources tell CBS2 the thieves were likely searching for a large sum of cash in the form of payments that had yet to be deposited to the bank.

Once the suspects left, Ethlin wiggled free from her restraints and called police.

“The officers entered the apartment and found her 91-year-old husband tied up and lying on the floor and he was unresponsive,” NYPD Deputy Chief Michael Kemper said.

The New York City Medical Examiner’s office ruled that Waldiman Thompson died from heart problems that were triggered by the incident — specifically, sudden cardiac death following home invasion with robbery and restraint in a person with hypertensive and atherosclerotic cardiovascular disease.