BALTIMORE (WJZ) -- As crews continue to clear rubble from the scene of the Baltimore explosion, investigators are still trying to determine what caused the blast.
Baltimore Gas & Electric reported initial indicators show the explosion was not caused by its equipment.
So what does that mean and how can customers detect an issue?
BGE says service is being restored to some customers, but the important work of finalizing a cause may take months.
- Baltimore Gas Explosion Kills 2, Injures 7; Crews Continue To Clear Rubble
- Baltimore Gas Explosion Victims Identified As Lonnie Herriott, Joseph Graham
- Mayor Warns Of Insurance Scam Targeting NW Baltimore Residents Following Explosion
- Investigation Continues In Deadly Baltimore Explosion, Data 'Indicative Of Some Type Of Issue Beyond BGE Equipment'
- Baltimore Gas Explosion: How To Help
Heroes who rushed to save their neighbors trapped in the rubble Monday heard the gas in the moments after.
"We could hear a hiss, and we were like, 'That's gas! We need to move!'" said Antoinetta Parrish.
"You could hear gas, like hiss, in the background. It was crazy," said Dean Jones.
BGE said homes passed their last inspections in June and July of 2019 and no leaks were reported along Labyrinth Road since 2014.
A spokesperson said it's too early to know the cause.
"BGE has checked and re-checked its equipment," spokeswoman Linda Foy said. "We have not found any issues with our equipment."
Foy later added crews are still working to restore gas service to homes along a main that was taken out of service as a precaution. Four homes that were demolished or condemned have had gas pipes disconnected.
Once the equipment in the area is cleared, gas service will be restored.
"If there is either structural damage or any customer gas equipment or piping that needs to be serviced (pre-existing conditional issues for instance), we will tag it out-of-service for the customer to have it inspected/repaired by a licensed plumber/appliance technician and then contact us to come back. Some of these residents have relocated temporarily so we'll also be leaving contact information so that these steps can take place when residents move back in," Foy wrote in a text message.
An investigation will likely take months, but a report is due to the state's public service commission within 30 days.
BGE said customers can be proactive in natural gas safety by using their senses.
Check for a rotten egg smell, a hissing sound, as described by neighbors after Monday's explosion or signs of dirt blowing or dead plants and grass, which could be a visual sign there could be a leak.
"There are a number of things customers can be mindful of, but the main thing and the most important thing is if you smell gas, leave the building and call BGE right away," Foy said.
Monday's explosion comes four years to the day of a gas explosion in Silver Spring in which seven people were killed and dozens more were injured. The incident was later blamed on faulty gas equipment.
In 2014, a child was killed in east Baltimore after a gas explosion sent debris flying, and in August 2019, a gas explosion leveled a shopping center in Columbia.
In a report released this week, the Public Service Commission placed fault for the 2019 explosion with BGE's equipment not conforming "to minimum safety standards."
BGE said there are about 250 other commercial sites with similar gas and electric lines the company is fixing.
"This work has already begun and it will be completed in 2021, so next year," Foy added.
BGE stressed to its customers that any gas appliances should be installed or worked on by licensed contractors.
"A professional, a contractor, needs to do that work," she said.
Federal agencies are on the ground to assist state and local investigators. The Public Service Commission has engineers on-site as well.
"We've had engineers on site since Monday's incident. In addition, BGE must file a written report of the incident within 30 days," the PSC said in a statement.
for more features.