By NBC4.com (Washington)

Photo Alan Etter Firefighters at the incident Monday.

WASHINGTON — Part of a D.C. neighborhood was blocked off on Monday evening after authorities found that a man had killed himself with cyanide.

Several rescue workers were taken to a nearby hospital.

Emergency responders said that at about 4:40 p.m., they were called to the 4300 block of 36th Street in Northwest because a woman was concerned that she had not seen her neighbor. The woman had a key to the man's home, so she let the firefighters, paramedics, a police officer and herself in to check on the neighbor.