TULSA, Oklahoma - Police, fire and medical crews rushed to downtown Tulsa Tuesday morning when at least nine people overdosed after apparently using K2 or synthetic marijuana outside the Iron Gate Soup Kitchen.

Shortly before 9 a.m., the firefighters and EMSA paramedics were sent 5th and Cincinnati for a report of multiple medical emergencies. Police  blocked traffic on Cincinnati between 5th and 6th Streets because of the number of ambulances at the scene. Ten ambulances in all responded.

Since then, EMSA says it's had a dozen other calls around the city. Police suspect they all used a form of the synthetic drug K2. Police say it's very dangerous because you never know where it's made or what's in it, but people think it's harmless because they can buy it at smoke shops and convenience stores.

Around the time people were finishing up breakfast and coffee at Iron Gage, people started passing out in the streets. When first responders arrived, people were lying in the streets and on sidewalks.

At least one was convulsing and several other people could be seen shaking, apparently from the effects of the drug.

Witnesses said the people gathered outside Iron Gate started smoking a form of K2. Minutes later - when the drug started to take effect - people started getting sick.

"It's like a freak accident - it's like from a horror movie or something," said witness Tim Merkov. 

Another man said he knew a lot of the victims, that they're hooked on K2 and apparently got a bad batch.

"It's a very dangerous situation, I can't stress that enough," Officer Leland Ashley said of the synthetic drug.

Ashley said it's hard to say exactly what the people were smoking given that the drugs sold as synthetic marijuana change ingredients rapidly to stay ahead of changes in law.

"Ingredients are banned and companies find another one to use in their products," he said. "It's almost like a 'tag you're it,' type of deal. It's a problem in the state of Oklahoma and nationally."

It's the first time in 32 years Captain Jerry Benefield has seen so many people with overdose symptoms being treated in a small area at the same time.

"The EMSA crews did a wonderful job, my crews did a wonderful job - we all worked together in unison," he said. "The police came over and helped us out, even the folks that work at this church that try and help these people were really very, very helpful."

EMSA says of the nine patients, one was in serious condition and six were in fair condition and were being treated for drug overdoses.

Communications Director Kelli Bruer said paramedics have responded to four other patients showing similar symptoms. They urge the public to be cautious in not ingesting anything that wasn't prescribed to them or that may have unknown ingredients. The other cases involve three women: ages 12, 16 and 20, and a 30-year-old man.

"It is not known that these calls are directly related; however, due the similarity and unusual number of patients in a short time frame, we are evaluating the situation," Bruer said.