A massive explosion at a fertilizer plant in the small Texas town of West has reduced dozens of homes to rubble. Officials believe five to 15 people have been killed but it's feared that dozens more may have died. More than 160 people have been injured and treated at local hospitals and search and rescue operations are under way.

This morning on “Starting Point” CNN’s Martin Savidge speaks to Waco Police Department Sgt. William Patrick Swanton about the next steps to come in the aftermath of the huge explosion.

Swanton says the weather “may slow [officials] a little bit” in their search and rescue efforts. He adds “on one hand it’s a good thing. Potentially it can help us with environmental issues – keeping particles out of the air. It can help with the fire from different homes that were ignited during the blast as well." Ultimately, Swanton says the weather "won’t stop us. It may slow us down but this will pass and we’ll get right back at it.”

“There’s a huge environmental issue,” says Swanton. He adds “Nails, broken boards, splinters boards can be a safety risk for those officers, firefighters, first responders, medical people going door to door.”

(CNN) - The Texas National Guard has sent 21 troops from a civil support team to monitor air quality near the blast, the Pentagon announced Thursday.