UPDATE: All six people who were hospitalized after carbon monoxide leak have been released.

On Sunday afternoon, friends and family of 13-year-old Watts, who died Saturday as a result of the toxic leak, released balloons into the sky outside the Quality Inn where the leak occurred.

UPDATE:

Six people remain in the hospital, one day after a deadly carbon monoxide leak at Quality Inn in Niles.

As of 10:30 a.m. Sunday, five children remained at Memorial Hospital in good condition, according to a spokeswoman.

A spokeswoman at Lakeland Health confirmed one patient is currently being treated. That person is also in good condition.

EARLIER:

A malfunctioning pool heater at a Niles caused a carbon monoxide leak that killed a teenager and sent 11 others to the hospital, officials said.

13-year-old Bryan Douglas Watts died when en-route to the hospital. Six other children, ranging 12-14 years of age, were sent to area hospitals. They're all expected to make a full recovery.

Just before 10 a.m. on Saturday, police and fire crews responded to the hotel on South 11th Street.

Hotel staff members called 911 after they walked by a window and saw six children unresponsive on the pool deck.

A seventh child was later found initially unresponsive and not breathing in a first-floor hotel room. Officials say the young girl was in the pool room just before the incident occurred. Medics were eventually able to revive her.

Carbon monoxide levels were later found to be 16 times the safe limit.

Investigators confirmed there was no carbon monoxide detector in the pool area.

Niles Fire Captain Don Wise said that this is one of the most tragic events he has witnessed in his 30-year career.

"To have six youths…that just takes it into a whole different category,” he said. “I hope I never have one of these again."

Francine Saunders was staying at the hotel at the time of the incident and witnessed the children when they were unresponsive.

"I couldn't even see them breathing," she recalled.

Dimetrius Butler, a victim of the carbon monoxide poisoning and friend of Watts remembers the events that occurred immediately before he became unresponsive.

"I was out of the pool and I passed out and I hit my head," he said.

Two Niles police officers, two Berrien County Sheriff's deputy, as well as one hotel employee were also taken to the hospital.

The law enforcement officers have been released, but at last check, the employee was still being treated.

The hotel had approximately 24 rooms booked at the time and all guests and staff were evacuated from the building. Currently, the hotel has been closed for occupancy while the investigation continues.

Choice Hotels, the owner of Quality Inn, said their "thoughts are with the families affected." The hotel is owned and operated by an independent franchisee.

A memorial has been set up outside the hotel in remembrance of Watts' life.