NOTE: This story has been updated.
A bicyclist was seriously injured in an accident in Northwest D.C. Monday morning.
It happened some time before 9 a.m. near 23rd and Constitution Ave. in Northwest D.C.
The bicyclist's wheel apparently fell off the bike, causing the crash. The bicyclist was flown to an area hospital.
U.S. Park Police and D.C. Fire and EMS responded.
Stay with NBCWashington.com for more.