The task to replace him comes at a critical time for Harvey residents and the south suburban city, which is currently in financial distress.
The council held a moment of silence for Clark, who died unexpectedly early Friday morning. His cause of death has not been released.
Clark was in his second term as mayor of the south suburban city of a little more than 20,000 people. He had about two years left on his current term.
"Mayor Clark was deeply committed to the city of Harvey and the people," said 1st Ward Ald. and Mayor Pro Tempore Drewenski. "His leadership and his dedication and his love for our community will not be forgotten."
Clark's family also attended Monday's meeting.
"We have endured a great loss to our city, but we still envision positive progress for Harvey, and we will not be divided," said Harvey resident Ruby Donahue.
The mayor was also a father and grandfather. He missed the most recent City Council meeting, and friends say he may have been ill at that time, but few suspected anything serious.
"Most of the council members, they're not thinking straight because they're still reeling in death of our beloved mayor," said 6th Ward Ald. Tyrone Rogers.
A memorial to Clark now sits inside Harvey City Hall. And as residents called for unity in the path forward, Harvey leadership remained divided over two alderpersons nominated to take over: Drewenski, and 5th Ward Ald. Dominique Randle-El.
No nominee received the required four votes necessary for appointment. As a result, Drewenski will continue to serve as mayor pro tempore.
"That means our mayor pro tem continues until such time as the city council meets again and in open meeting nominates someone who receive four votes," said Harvey City Attorney Keri-Lyn Krafthefer.
Clark's passing comes as the town of Harvey has been dealing with a financial crisis. It is in debt by around $150 million and has been forced to lay off many city workers, including more than half of the fire department employees and over a third of the police.
It is a stressful time for the city's elected leaders, who have appealed to the federal and state governments for help.
They are now waiting on the General Assembly to approve Harvey's application to be declared "financially distressed." The designation would free up desperately needed emergency funding.
"We can power through challenging times. We're still standing. And we would want to carry forth Mayor Clark's legacy to make sure that the people of Harvey have streets, lights, curbs, sidewalks, police and fire protection. That was his mantra to all of us and we want to keep that going forward," Krafthefer said.
Alderpersons will get another chance to vote at the next special city council meeting. It is still unclear when that meeting will be held.
Should one of the six alderpersons who serve on the council receive the required four votes and be appointed acting mayor, that individual will be required to either resign from their aldermanic seat, allowing the city council to appoint a replacement or leave the seat vacant for the remainder of the term until the next election, Harvey officials said.