A 67-year-old man died after he collapsed at his home in Washington, D.C. and first responders sent to help him ended up across the street, according to the fire department.

It's the latest emergency response failure in the district.

D.C. Fire and EMS Chief Gregory Dean said first responders were dispatched within minutes after Albert Jackson suffered a heart attack and collapsed Sunday. His wife, Gloria, called 911 as her grandson performed CPR.

An ambulance arrived quickly on Jackson's street, but the problem, Dean said, is that firefighters tried to help the wrong victim. They saw D.C. police helping someone on the sidewalk and assumed it was the same person who called them, Dean said. Since police said the person was OK, the firefighters left.

"They made the assumption that that was the right location," Dean said. "They had the other units put back in service and they returned to quarters."

Gloria Jackson called 911 again.

When paramedics returned to the correct location, almost 20 minutes had passed since the first dispatch. Jackson was taken to the hospital but did not survive.

"He loved his grandkids, he loved his family and he was a nice man," Gloria Jackson said.

Dean said he is changing procedure as a result. Now, firefighters arriving at the scene of a call will be required to give dispatchers the address of their location in order to confirm they're at the right place.

"If we have holes in our system, we're supposed to look at," Dean said. "Do we need to take time to see if our processes are right?"

The firefighters' supervisor will determine whether to take disciplinary action.