Li tried again. Thirty seconds later, his call went through to Crenshanda Williams. "Houston 9-1-1, do you need medical, police or fire?" she asked.
"This is a robbery," Li blurted out.
Li heard a sigh, then nothing. The call had been disconnected again.
On Wednesday, Williams was sentenced to 10 days in jail and 18 months on probation after she was convicted of hanging up on thousands of calls during the 18 months that she worked as a 911 dispatcher for the city of Houston, according to the Houston Chronicle.
When investigators asked why she had hung up on so many people, she told them that sometimes she just didn't feel like talking.
Franklin Bynum, Williams' attorney, told the Houston Chronicle that the case had unearthed systemic problems at the city's emergency centre, which had consolidated calls for police, the fire department and paramedics 15 years ago.
He said that one of the problems was that the system drops calls instead of rerouting them if dispatchers aren't ready for them - and that his client was a scapegoat for a broken system.
"She was going through a hard time in her life, and she was a poor-performing worker at the Houston Emergency Center," he said.
"But punishing her doesn't do anything to fix the problems that still exist at the emergency centre."
Williams' supervisor was put on internal probation for a year, the Chronicle reported, but a jury found Williams criminally responsible for ignoring thousands of calls.
Williams had started working as a dispatcher in July 2014 and had taken thousands of calls, court documents say. But an audit a year and a half after she was hired found that an abnormally large number of her calls had lasted 20 seconds or less, and the city began an investigation.
The disconnected calls include one from March 13, 2016, during which a security guard named Jimmie Moten Jr. dialled 911 from his cellphone to report that two people in trucks were racing on Interstate 45.
"This is Officer Moten. I'm driving on 45 South right now and right now I am at -" he said before he was cut off by Williams.
"Ain't nobody got time for this. For real," she said, then the line went dead.
When investigators pressed Williams about the calls, she admitted she was the call-taker on both, court documents say.
Williams, court documents say, "admitted that she often hangs up on calls that have not been connected because she did not want to talk to anyone at the time."
The consolidated center for 911 calls opened in 2003 and handles millions of calls every year, according to the Chronicle, or 9,000 a day. Two-thirds of those calls aren't true emergencies.
The rest involve people in dire need.
"The citizens of Harris County rely on 911 operators to dispatch help in their time of need," Assistant District Attorney Lauren Reeder told Houston Fox affiliate KRIV.
"When a public servant betrays the community's trust and breaks the law, we have a responsibility to hold them criminally accountable."