A mail carrier was attacked on Milwaukee's west side late Wednesday morning and a witness with a gun stopped the attempted sexual assault.

"I heard some gunshots like three or four and I jumped right over my baby while it was happening and I was scared. Trying to be nosey, looked out the window, ran through the building, ran out the door and be nosey and I saw her crawling towards the mail truck," said Ashanti East, a witness.

Witnesses said the mail truck was parked near the corner of 32nd and Wells Streets.

"So when I see the mail lady she was like kind of scared. Like didn't know what to do like 'Ahhh' screaming," said Trina Harris, a witness.

Police said a witness tried to help, firing a gun into the ground. The suspect then tried to assault the witness.

"When she was shooting it's like she kind of was shooting in the air. She really wasn't trying to shoot at him, but she's basically letting him know I will shoot you," Harris said.

Witnesses said the 28-year-old suspect tried to get away.

"The guy he tried to run in the back," Harris said.

Police said the alleged attacker was combative with officers, but they managed to arrest the suspect.

Neighbors are concerned how their reliable mail woman is holding up Wednesday night.

"That's said cause she don't bother nobody. She's quiet. She come on time, grab mail and she leaves back out," said Shana Woods, neighbor.

The U.S. Postal Service confirmed it's working with Milwaukee Police, conducting an investigation into an incident involving a letter carrier Wednesday.