Eight people were being treated for non-critical injuries at Baystate Medical Center's emergency room, spokeswoman Jane Albert told WWLP-TV, Springfield.
Another eight patients, including two firefighters, were at Mercy Medical Center, spokeswoman Mary Orr said.
A Columbia Gas spokesperson told the TV station two workers were injured in the explosion but were expected to survive.
The explosion knocked people standing nearby to their feet, and it could be heard from as far away as Hardwick, Granby, Belchertown and Monson, the report said.
Ray Liotta sues skin care company over use of likeness
NBC reportedly holds celebs hostage to Jimmy Fallon's show