"We're all brothers and sisters and we're all here for each other, you know, so we're one big family and I miss that guy already," said Mateo Crawford.
PREVIOUS REPORT: USPS worker killed in collision in Santa Rosa, police say
Mateo Crawford worked with Hernandez and just like those who attended the vigil, he's heartbroken.
We spoke with another of Irvin's co-workers, Chad Lamb who is the union president of the Santa Rosa branch.
"He was always positive, always a smile on his face - he never said anything bad about anybody, he was always a very positive figure in the office," said Lamb.
"One of those people that would make you smile and laugh no matter when you were expecting it, or if you needed it, you know he would automatically do that," said Crawford.
Santa Rosa police say it appears that the driver of an SUV was driving erratically prior to the collision and struck the postal vehicle and Hernandez as he was standing outside of it, sorting mail. Officers believe the driver of the SUV had some sort of medical emergency but haven't expanded on that. It certainly highlights one of the many dangers that carriers are now dealing with.
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Lamb says there are new postal service trucks where mail sorting is done on the side of the truck versus the back. It's unclear if that would have helped here but those vehicles should be coming here in the next few years.
Tuesday afternoon, Hernandez's spot in the parking lot of the USPS was left open, with just a flower there in his memory.
The quote on Irvin's Instagram page shows the kind of positivity the young letter carrier had saying, "I'm good in life, no complaints of where I am or where I'm going."
Lamb says Irvin's death is hitting hard and he's asking those in the community for support when they see their letter carrier.
"Say hi, say a kind thing to our carriers right now, and be supportive," said Lamb.
"That is a good message for the community there to let them know that you folks are hurting right now," said ABC7 News reporter J.R. Stone.
"We are hurting. I talked with several of the carriers today and there is not a single carrier who is not hurting one way or another and they really do need the support," responded Lamb.
Irvin's family has set up a GoFundMe page to help during this difficult time. To make a donation, visit here.