A maintenance worker is recovering in hospital after he was exposed to a chemical while working at a northeast Calgary hotel.

It happened at the Coast Plaza Hotel just before 2:00 p.m. Tuesday afternoon.

District Chief Paul LeBlanc with the Calgary Fire Department says a maintenance worker was mixing a batch of chemicals in the basement.

“It was chlorine for the pool,” says Le Blanc. “That chemical reacted but we’re not sure why it reacted the way it did.”

He was assessed by paramedics and found to be in respiratory distress and was transported to the Foothills Medical Centre and his condition is not known.

Fifty guests and 16 staff have been evacuated from the north tower of the Coast Plaza Hotel as firefighters investigate the situation.

“Our crews have gone in to do an assessment,” says LeBlanc. “They’ve identified it’s chlorine and they’re neutralizing it at this point.”

A second individual was assessed by paramedics for precautionary reasons but he was unharmed and released on scene.

Late Tuesday evening, Calgary EMS announced it had assessed a third person, an adult male, paramedics determined he was uninjured and was released.

Crews remained on scene late into the night to ensure the hotel was properly ventilated.