A terrified man ran from house to house claiming he was being chased by criminals and saying he would never see his children again.
Hours later, he was pronounced dead in hospital.
Daniel Morris (35), of Allenton Drive, Tallaght, drove his Volvo car into railings in Limekiln Avenue, Greenhills, shortly after 9pm on Friday.
He then ran into the nearby Manor estate where he began banging on doors.
At the end of Temple Manor Drive he ran into a house after the owner opened the door.
"He was very distressed and saying 'I'll never see my kids again' and 'They're going to shoot me', but there didn't appear to be anyone after him," the man said.
"Then he ran out the door. We would have preferred if he stayed. He was very anxious."
Mr Morris then ran into the house next door. The occupant, Davina Byrne, said: "I let him in, and I'm glad I did. He was terrified. I really feel for his family.
"He was shouting 'Let me in' and 'Someone's after me, they have guns'. He didn't want me to open the door once he was in.
"Then he clutched at his heart and collapsed. Soon after, gardai arrived, and then the ambulance."
Other neighbours saw paramedics working for some time on Mr Morris before he was taken by ambulance to Tallaght Hospital where he was later pronounced dead.
A post-mortem examination was due to be carried out yesterday.
One man said Mr Morris had been bleeding from one ear and that his eyes were "rolling", possibly as a result of injuring his head when he crashed his car.
A large number of family, friends and neighbours gathered yesterday at his home to console his family but declined to comment on the incident when asked.
Investigators are trying to piece together Mr Morris' last movements before the crash.
Toxicology tests will form a crucial role in the investigation to see if he may have been under the influence of any substances at the time of the incident.
The matter has been referred to the Garda Siochana Ombudsman Commission.
Gardai want to talk to anyone who witnessed the initial crash in Limekiln Avenue or who may have been in the Temple Manor area between 9pm and 10pm on Friday.
They are asked to get in touch with Crumlin Garda Station on 01 666 6200.