“Enough is enough of wild speculation.”

Houston Mayor John Whitmire was frustrated as he stood in front of the cameras alongside the police chief last month, trying to dispel the rumors that have cast a veil of anxiety over the vast network of bayous that crisscross his city.

“There is no evidence that there is a serial killer loose on the streets of Houston,” Whitmire said at the news conference.

A crescendo of nervous speculation reached fever pitch in the city when the body of 20-year-old University of Houston student Jade McKissic was pulled from Brays Bayou on September 15 – one of seven deaths reported in Houston area bayous last month.

The promising honors student had mysteriously vanished after spending an evening with friends at a local bar then leaving alone without her cellphone and stopping at a gas station next door, Houston police said. An autopsy revealed “no signs of trauma or foul play,” but the cause and manner of McKissic’s death remain pending, according to the Harris County Institute of Forensic Sciences.

“That was probably the biggest deal…that’s when college students started getting really worried,” Houston Council Member Letitia Plummer said.

Alarmed by the chain of bodies pulled out of bayous, some Houston residents took to social media to try to make sense of the deaths, with posts pushing theories of a serial killer garnering thousands of likes. Family members of some of those found in the waterways have also shown skepticism over the death investigations and called for more answers.

Last week, the father of Kenneth Cutting Jr., a 22-year-old found dead in Buffalo Bayou last year, expressed frustration with authorities after the medical examiner listed his son’s cause of death as undetermined.

“He did not fall in that bayou,” the father Kenneth Cutting Sr. told CNN affiliate KHOU. “I don’t know if there’s a serial killer but the way that they’re dealing with these bodies is ridiculous.”

Meanwhile, local officials like Plummer and Council Member Carolyn