This is the third attack involving the Muni T-line. All three attacks happened within a few blocks of each other on Third Street corridor and they all happened during the evening hours.
The 29-year-old man told police he was attacked by five young men between the ages of 14 and 16 inside the Muni light rail on Third Street and Williams Avenue.
"We're dealing with suspects who are cowards, they are basically picking on the most vulnerable people who are harmless and they are just beating them up for no reason just to get a laugh," says Samson Chan from the San Francisco Police Department.
The attack was similar to the one back on Jan. 24 when a 83-year-old man was kicked and punched on the same Third Street corridor. He died two months later.
And a week ago, five teenagers surrounded a 57-year-old woman on the Muni platform on Third Street. The surveillance camera recorded a 15-year-old grabbing her by the neck and throwing her on to the rails. He has been arrested. The woman is recovering.
Police are investigating whether any of these cases are related.
Vicky Platero told ABC7 she too was robbed on the T-line.
"It's the teenagers that are doing this, it's the kids that are doing this. It's not older people," says Platero. She says she knows this, "because it happened to me. They took my Blackberry."
Police said they have increased their presence on the T-line. While they are patrolling the area, ABC7 did not see a single uniformed police officer on Muni while our cameras were there.
"None, none. I have never seen an officer on this train. I'm here in the morning and I'm here at night," says passenger Elaine Celestan.
"A lot of them are not in uniform, but in street clothes. If these suspects see officers in uniform, obviously they are not going to commit their crimes, so we have different strategies we are utilizing," says Chan.
Police say they do not have surveillance video of this most recent attack on Saturday night because it occurred inside the light rail train.
As for the 83-year-old man who was first attacked and later died, police are now treating that as a homicide.