This may explain some of the train delays today: The police were investigating a customer injury that caused delays on the F and the G lines. It appears that someone jumped in front of a train at the 15th Street/Prospect Park station in Windsor Terrace, Brooklyn. Trains should be running again now. The condition of the victim is unclear, but we're hearing that he may have stabbed two people before jumping in front of the train. Update below.

UPDATE: Early reports are now implying that the man jumped in front of a G train after stabbing two people—a man and a woman, likely his parents. The victims were both taken to Methodist hospital where the woman was declared dead on arrival and the man is said to be in very critical condition. The condition of the jumper remains unclear.

UPDATE 2: The Daily News adds a little bit more info: The stabbings took place around 8:15 a.m. in the victim's Howard Place residence and while the parents were taken to Methodist Hospital, the alleged stabber was taken to Lutheran Medical Center where he is in critical condition.

Meanwhile a tipster sends in this grisly report from the scene which verifies the jumper's reported condition:

I was on the F train right behind the G train that the guy jumped in front of. As we were exiting through the F train and then onto the G train and then onto the platform, I could hear the man screaming under the train and the cops on the platform were reassuring him that they would get to him soon. So I don't think he died immediately and seemed to be under the last G train car.

On the scene at Howard Place, The Post found a neighbor who reports there "was blood everywhere" after the attack.

UPDATE 3: We have more coverage here.