PHILADELPHIA (CBS) – Philadelphia police are asking residents to be on alert after a man pretended to be a Philadelphia Water Department employee during a robbery in the city’s Grays Ferry section last month. Police say on April 23 the suspect was seen on surveillance video walking in the area of the 3600 block of Wharton Street and looking at residences.

The suspect wore dark clothes and a bright safety vest and identified himself as a Philadelphia Water Department employee to trick the victim into letting him into her house. Once he was inside, police say he attacked her.

“He goes to the kitchen, fills up some vile or tube with water saying he has to test it. He then tells the victim to close the door because it’s too bright. When she does that, he goes behind her, he grabs her aggressively, forcefully. She fights mightily, tremendous courage on the part of the victim. A struggle ensues and, ultimately, he does flee the location after taking her cellphone,” said Philadelphia Police Capt. Sekou Kinebrew.

Kinebrew said the victim’s family member then chased after the suspect.

“Another family member comes down the steps after hearing the commotion, chases him a little bit outside, sees him drop the cellphone, so we do have that back, but it’s still horrible and a harrowing experience for the victim,” said Kinebrew.

The victim suffered an injury to her face from the struggle.

Some neighbors found out what was going on through a citizen alert app.

“I saw the notification and then we came outside, and she was right outside. She was bleeding, I think she lost a tooth and then she was pretty shaken,” said neighbor Rabin Budhathoki.

As police work to identify the suspect, they want everyone to know about a simple program they launched a few years ago called Be Sure If You Open The Door. If you feel uncertain about a person claiming to be a utility worker in person or on the phone, call 911 and the call center will verify with the utility companies for you.

“If you made that call to 911 and we’re able to confirm that there is no service on your block, the 911 will dispense a police officer,” explained Kinebrew.

If you have any information on this incident, call police.