WATERLOO, Iowa --- The thump came a few minutes after Tai-Lin Phillips went to the bathroom of his small apartment.
When acquaintances who heard the noise went to check on him, they found Phillips on the floor unconscious.
One of the people in the apartment, 39-year-old Vonvette "Von" Leroy Sawyers would later tell police and friends he gave Phillips CRP.
Someone called 911.
Paramedics arrived and took Phillips to Allen Hospital, but he never regained consciousness and was declared dead.
A medical examiner later determined Phillips --- a 41-year-old father of four who was living in a transitional home on Lafayette Street --- died from "mixed drug toxicity," a combination of heroin and alcohol.
Within weeks, a federal grand jury indicted Sawyers, Mark Deland Wilson-Bey and Lewis "Junior" Boldon for conspiracy to distribute heroin. Court records allege Wilson-Bey made a delivery on Nov. 3, the day Phillips collapsed.
Phillips wife, Kiki Phillips, denies her husband was a heroin addict. She said he had used marijuana in the past and battled an earlier crack cocaine habit.
"I believe someone else injected him with it," Kiki Phillips said. "If he shot himself with a needle, where's the needle?"
A deadly opiate, heroin is seeing a resurgence in Iowa, according to drug enforcement agents and treatment officials. Still, other drugs like methamphetamine and marijuana are more prevalent.
"There is no doubt that it is available," said Scott Smith, the resident agent in charge of the U.S. Drug Enforcement Administration's office in Cedar Rapids. He is part of a law enforcement task force charged with tackling the recent flood of brown heroin from Mexico.
There have been deaths --- 22 in the area stretching from Iowa City to Cedar Rapids to Waterloo in the past 18 months, Smith said. Numbers for Black Hawk County weren't available, but the DEA's assessment noted an increase in both fatal and non-fatal heroin overdoses in Linn and Scott counties in Iowa between 2008 and 2010.
In 2009, local drug officers seized only 10 grams of heroin in Black Hawk County. A year later, it was 129 grams. Figures for 2011 weren't yet available.
And there are other signs of heroin's presence.
In November 2010, a woman fell from the window of her downtown third-floor apartment. She survived with a broken arm but was difficult to understand for officers trying to find out who she was and how she fell. Inside her apartment they found six small bags of heroin on her dining room table.
In November 2011, medics were called when a body was found in a Johnson Street apartment. When they took the deceased to the hospital, they found an extra needle among their supplies. Relatives told police they suspected the man was a heroin user. Officers found prescription methadone bottles and a plastic bag with "white contents," according to court records. A death certificate has yet to be filed.
Dispatched to a suspicious vehicle call on Byron Avenue on Dec. 31, officers found a syringe and a capsule with heroin residue.
Treatment workers saw an increase in heroin and prescription opiate patients about six months ago, although that trend has since dropped off, said Chris Hoffman with Pathways Behavioral Services.
He said drug use is cyclical. There were was a tide of heroin in the early 1970s. It subsided for a while but made a comeback in the late 1980s and early 1990s.
"Heroin doesn't go away. You just quit hearing about it," Hoffman said.
The drug is smuggled from south of the border. Most of the powder that reaches Waterloo is trafficked by Chicago-area gangs, Smith said. He said the purity levels found in Northeast Iowa are astonishing.
Smith worked at five other DEA offices before landing in Iowa. When he was in Texas, he saw heroin that was only about 17 to 18 percent pure. In Oklahoma City, black tar heroin there was in the low 40s.
The brown heroin that has been making its way to Iowa is around 50 percent pure.
"I'm truly surprised we don't have more fatalities, because that is strong heroin," Smith said.
Heroin users quickly develop a tolerance, which forces them to take more to experience the same high.
"This cat and mouse game with the volatile, unpredictable purity levels of heroin plays a significant role in the amount of overdoses our area is experiencing," Smith said.
The drug is reaching a suburban, middle class market in the state, according to an Iowa Office of Drug Control Policy report. Although there are a number of older, long-time users, the current average user is in his or her mid-20s, Smith said.
Heroin is also filling a void for residents addicted to prescription opioid-based painkillers who are seeking a cheaper way to maintain their habits.
One example cited in the DEA's recently released National Drug Threat Assessment put it this way: Heavy oxycodone users may need to take up to 400 mg a day to feed their habit. That costs $400. Users can get the same effect with heroin for a fraction of the cost.
On the law enforcement side, officers are dismantling some of the organizations that allegedly bring heroin into Northeast Iowa from Chicago.
In February 2011, drug agents with the Waterloo-based Tri-County Drug Enforcement Task Force and other agencies raided 17 homes under the cover of early morning darkness finding heroin, methadone, oxycodone and guns. Eight people --- several with prior drug convictions in Cook County, Ill., where Chicago is located --- were indicted for conspiracy to possess heroin with intent to distribute and other charges. The first trial was scheduled for last week.
Court records allege the heroin ring that involved Sawyers, Wilson-Bey and Bolden operated in Iowa as far back as January 2007.
Smith said the heroin probe is so vast it split into branches, with a separate round of indictments coming from Cedar Rapids. He estimates there will about 75 to 100 indictments by the time all the cases play out.
Meanwhile, Tai-Lin Phillips's wife struggles with how to explain the death to his children.
"You don't want them to have the stain of 'your dad was a heroin addict,' when he wasn't," she said.
Tai-Lin Phillips graduated from Hawkeye Community College and taught computer programing at the Computer Learning Center in Chicago.
"He was a hard worker," she said.
She is also trying to sort out the facts. She said those who were in the apartment gave conflicting accounts of what happened.
"They gave me three different stories in the first few minutes of the whole situation," she said.